3551391540 has 144 divisors (see below), whose sum is σ = 11223838080. Its totient is φ = 942606720.

The previous prime is 3551391539. The next prime is 3551391553. The reversal of 3551391540 is 451931553.

It is a happy number.

3551391540 is a `hidden beast` number, since 3 + 5 + 513 + 91 + 54 + 0 = 666.

It is a super-2 number, since 2×3551391540² = 25224763740767143200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 3551391495 and 3551391504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1111345 + ... + 1114535.

It is an arithmetic number, because the mean of its divisors is an integer number (77943320).

Almost surely, 2^3551391540 is an apocalyptic number.

3551391540 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3551391540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5611919040).

3551391540 is an abundant number, since it is smaller than the sum of its proper divisors (7672446540).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3551391540 is a wasteful number, since it uses less digits than its factorization.

3551391540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3444 (or 3430 counting only the distinct ones).

The product of its (nonzero) digits is 40500, while the sum is 36.

The square root of 3551391540 is about 59593.5528392124. The cubic root of 3551391540 is about 1525.6895980008.

The spelling of 3551391540 in words is "three billion, five hundred fifty-one million, three hundred ninety-one thousand, five hundred forty".