617657172021 has 12 divisors (see below), whose sum is σ = 892539711648. Its totient is φ = 411601490664.

The previous prime is 617657171983. The next prime is 617657172029. The reversal of 617657172021 is 120271756716.

617657172021 is a `hidden beast` number, since 6 + 1 + 7 + 6 + 571 + 72 + 0 + 2 + 1 = 666.

617657172021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 617657172021 - 2¹¹ = 617657169973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (617657172029) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14140095 + ... + 14183708.

It is an arithmetic number, because the mean of its divisors is an integer number (74378309304).

Almost surely, 2^617657172021 is an apocalyptic number.

It is an amenable number.

617657172021 is a deficient number, since it is larger than the sum of its proper divisors (274882539627).

617657172021 is a wasteful number, since it uses less digits than its factorization.

617657172021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28326232 (or 28326229 counting only the distinct ones).

The product of its (nonzero) digits is 246960, while the sum is 45.

The spelling of 617657172021 in words is "six hundred seventeen billion, six hundred fifty-seven million, one hundred seventy-two thousand, twenty-one".