21771309954 has 16 divisors (see below), whose sum is σ = 45044089920. Its totient is φ = 7006858320.

The previous prime is 21771309929. The next prime is 21771310007. The reversal of 21771309954 is 45990317712.

It is a super-2 number, since 2×21771309954² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62561062 + ... + 62561409.

It is an arithmetic number, because the mean of its divisors is an integer number (2815255620).

Almost surely, 2^21771309954 is an apocalyptic number.

21771309954 is an abundant number, since it is smaller than the sum of its proper divisors (23272779966).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21771309954 is a wasteful number, since it uses less digits than its factorization.

21771309954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125122505.

The product of its (nonzero) digits is 476280, while the sum is 48.

It can be divided in two parts, 2177 and 1309954, that added together give a palindrome (1312131).

The spelling of 21771309954 in words is "twenty-one billion, seven hundred seventy-one million, three hundred nine thousand, nine hundred fifty-four".