68656621 has 4 divisors (see below), whose sum is σ = 74898144. Its totient is φ = 62415100.

The previous prime is 68656603. The next prime is 68656631. The reversal of 68656621 is 12665686.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 68656621 - 2⁷ = 68656493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68656631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3120745 + ... + 3120766.

It is an arithmetic number, because the mean of its divisors is an integer number (18724536).

Almost surely, 2^68656621 is an apocalyptic number.

It is an amenable number.

68656621 is a deficient number, since it is larger than the sum of its proper divisors (6241523).

68656621 is a wasteful number, since it uses less digits than its factorization.

68656621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6241522.

The product of its digits is 103680, while the sum is 40.

The square root of 68656621 is about 8285.9290969692. The cubic root of 68656621 is about 409.4750787778.

The spelling of 68656621 in words is "sixty-eight million, six hundred fifty-six thousand, six hundred twenty-one".