21371955371 has 16 divisors (see below), whose sum is σ = 23118482688. Its totient is φ = 19640253600.

The previous prime is 21371955361. The next prime is 21371955377. The reversal of 21371955371 is 17355917312.

It is a cyclic number.

It is not a de Polignac number, because 21371955371 - 2³⁴ = 4192086187 is a prime.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21371955377) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3383306 + ... + 3389616.

It is an arithmetic number, because the mean of its divisors is an integer number (1444905168).

Almost surely, 2^21371955371 is an apocalyptic number.

21371955371 is a deficient number, since it is larger than the sum of its proper divisors (1746527317).

21371955371 is a wasteful number, since it uses less digits than its factorization.

21371955371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7442.

The product of its digits is 198450, while the sum is 44.

The spelling of 21371955371 in words is "twenty-one billion, three hundred seventy-one million, nine hundred fifty-five thousand, three hundred seventy-one".