68691621 has 4 divisors (see below), whose sum is σ = 91588832. Its totient is φ = 45794412.

The previous prime is 68691589. The next prime is 68691643. The reversal of 68691621 is 12619686.

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 68691621 - 2⁵ = 68691589 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 68691621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68691661) 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, 11448601 + ... + 11448606.

It is an arithmetic number, because the mean of its divisors is an integer number (22897208).

Almost surely, 2^68691621 is an apocalyptic number.

It is an amenable number.

68691621 is a deficient number, since it is larger than the sum of its proper divisors (22897211).

68691621 is a wasteful number, since it uses less digits than its factorization.

68691621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22897210.

The product of its digits is 31104, while the sum is 39.

The square root of 68691621 is about 8288.0408420808. The cubic root of 68691621 is about 409.5446481453.

The spelling of 68691621 in words is "sixty-eight million, six hundred ninety-one thousand, six hundred twenty-one".