351821556 has 120 divisors (see below), whose sum is σ = 983739680. Its totient is φ = 109315008.

The previous prime is 351821551. The next prime is 351821557. The reversal of 351821556 is 655128153.

It is a happy number.

It is a super-2 number, since 2×351821556² = 247556814532522272, which contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 351821556.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (351821551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 412026 + ... + 412878.

Almost surely, 2^351821556 is an apocalyptic number.

351821556 is a gapful number since it is divisible by the number (36) 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 351821556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (491869840).

351821556 is an abundant number, since it is smaller than the sum of its proper divisors (631918124).

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

351821556 is a wasteful number, since it uses less digits than its factorization.

351821556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 955 (or 944 counting only the distinct ones).

The product of its digits is 36000, while the sum is 36.

The square root of 351821556 is about 18756.9068878640. The cubic root of 351821556 is about 705.9503344968.

The spelling of 351821556 in words is "three hundred fifty-one million, eight hundred twenty-one thousand, five hundred fifty-six".