661547340 has 72 divisors (see below), whose sum is σ = 2015814528. Its totient is φ = 175610880.

The previous prime is 661547323. The next prime is 661547351. The reversal of 661547340 is 43745166.

It is a happy number.

661547340 is a `hidden beast` number, since 6 + 615 + 4 + 7 + 34 + 0 = 666.

It is a super-2 number, since 2×661547340² = 875289766122151200, 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 = 661547295 and 661547304.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31900 + ... + 48380.

It is an arithmetic number, because the mean of its divisors is an integer number (27997424).

Almost surely, 2^661547340 is an apocalyptic number.

661547340 is a gapful number since it is divisible by the number (60) 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 661547340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1007907264).

661547340 is an abundant number, since it is smaller than the sum of its proper divisors (1354267188).

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

661547340 is a wasteful number, since it uses less digits than its factorization.

661547340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16719 (or 16714 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The square root of 661547340 is about 25720.5625910477. The cubic root of 661547340 is about 871.3386447176.

The spelling of 661547340 in words is "six hundred sixty-one million, five hundred forty-seven thousand, three hundred forty".