21477477140738 has 4 divisors (see below), whose sum is σ = 32216215711110. Its totient is φ = 10738738570368.

The previous prime is 21477477140701. The next prime is 21477477140747. The reversal of 21477477140738 is 83704177477412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21140748780649 + 336728360089 = 4597907^2 + 580283^2 .

It is a super-2 number, since 2×21477477140738² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5369369285183 + ... + 5369369285186.

Almost surely, 2^{21477477140738} is an apocalyptic number.

21477477140738 is a deficient number, since it is larger than the sum of its proper divisors (10738738570372).

21477477140738 is a wasteful number, since it uses less digits than its factorization.

21477477140738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10738738570371.

The product of its (nonzero) digits is 51631104, while the sum is 62.

The spelling of 21477477140738 in words is "twenty-one trillion, four hundred seventy-seven billion, four hundred seventy-seven million, one hundred forty thousand, seven hundred thirty-eight".