621616655 has 8 divisors (see below), whose sum is σ = 813752784. Its totient is φ = 452084800.

The previous prime is 621616649. The next prime is 621616663. The reversal of 621616655 is 556616126.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 621616655 - 2⁶ = 621616591 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5651006 + ... + 5651115.

It is an arithmetic number, because the mean of its divisors is an integer number (101719098).

Almost surely, 2^621616655 is an apocalyptic number.

621616655 is a deficient number, since it is larger than the sum of its proper divisors (192136129).

621616655 is a wasteful number, since it uses less digits than its factorization.

621616655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11302137.

The product of its digits is 64800, while the sum is 38.

The square root of 621616655 is about 24932.2412751040. The cubic root of 621616655 is about 853.4423974403.

The spelling of 621616655 in words is "six hundred twenty-one million, six hundred sixteen thousand, six hundred fifty-five".