621542645 has 16 divisors (see below), whose sum is σ = 774923760. Its totient is φ = 478001664.

The previous prime is 621542641. The next prime is 621542651. The reversal of 621542645 is 546245126.

It can be written as a sum of positive squares in 8 ways, for example, as 237169 + 621305476 = 487^2 + 24926^2 .

It is not a de Polignac number, because 621542645 - 2² = 621542641 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621542641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24587 + ... + 42983.

It is an arithmetic number, because the mean of its divisors is an integer number (48432735).

Almost surely, 2^621542645 is an apocalyptic number.

It is an amenable number.

621542645 is a deficient number, since it is larger than the sum of its proper divisors (153381115).

621542645 is a wasteful number, since it uses less digits than its factorization.

621542645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18664.

The product of its digits is 57600, while the sum is 35.

The square root of 621542645 is about 24930.7570081616. The cubic root of 621542645 is about 853.4085256651.

The spelling of 621542645 in words is "six hundred twenty-one million, five hundred forty-two thousand, six hundred forty-five".