68031667621 has 4 divisors (see below), whose sum is σ = 68051639232. Its totient is φ = 68011696012.

The previous prime is 68031667619. The next prime is 68031667657. The reversal of 68031667621 is 12676613086.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12676613086 = 2 ⋅6338306543.

It is a cyclic number.

It is not a de Polignac number, because 68031667621 - 2¹ = 68031667619 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 (68031667661) 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, 9980695 + ... + 9987508.

It is an arithmetic number, because the mean of its divisors is an integer number (17012909808).

Almost surely, 2^68031667621 is an apocalyptic number.

It is an amenable number.

68031667621 is a deficient number, since it is larger than the sum of its proper divisors (19971611).

68031667621 is a wasteful number, since it uses less digits than its factorization.

68031667621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19971610.

The product of its (nonzero) digits is 435456, while the sum is 46.

The spelling of 68031667621 in words is "sixty-eight billion, thirty-one million, six hundred sixty-seven thousand, six hundred twenty-one".