21377973617 has 32 divisors (see below), whose sum is σ = 28896134400. Its totient is φ = 15273457920.

The previous prime is 21377973577. The next prime is 21377973623. The reversal of 21377973617 is 71637977312.

It is not a de Polignac number, because 21377973617 - 2⁸ = 21377973361 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21377973647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 77483 + ... + 220815.

It is an arithmetic number, because the mean of its divisors is an integer number (903004200).

Almost surely, 2^21377973617 is an apocalyptic number.

It is an amenable number.

21377973617 is a deficient number, since it is larger than the sum of its proper divisors (7518160783).

21377973617 is a wasteful number, since it uses less digits than its factorization.

21377973617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143513.

The product of its digits is 2333772, while the sum is 53.

The spelling of 21377973617 in words is "twenty-one billion, three hundred seventy-seven million, nine hundred seventy-three thousand, six hundred seventeen".