621512172 has 18 divisors (see below), whose sum is σ = 1571044748. Its totient is φ = 207170712.

The previous prime is 621512159. The next prime is 621512191. The reversal of 621512172 is 271215126.

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8632078 + ... + 8632149.

Almost surely, 2^621512172 is an apocalyptic number.

It is an amenable number.

621512172 is an abundant number, since it is smaller than the sum of its proper divisors (949532576).

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

621512172 is a wasteful number, since it uses less digits than its factorization.

621512172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17264237 (or 17264232 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 621512172 is about 24930.1458479488. The cubic root of 621512172 is about 853.3945784628.

Adding to 621512172 its reverse (271215126), we get a palindrome (892727298).

The spelling of 621512172 in words is "six hundred twenty-one million, five hundred twelve thousand, one hundred seventy-two".