21755065551731 has 8 divisors (see below), whose sum is σ = 22481403227184. Its totient is φ = 21038746327200.

The previous prime is 21755065551719. The next prime is 21755065551749. The reversal of 21755065551731 is 13715556055712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21755065551731 is a prime.

It is a super-2 number, since 2×21755065551731² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21755065551431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2504608316 + ... + 2504617001.

It is an arithmetic number, because the mean of its divisors is an integer number (2810175403398).

Almost surely, 2^{21755065551731} is an apocalyptic number.

21755065551731 is a deficient number, since it is larger than the sum of its proper divisors (726337675453).

21755065551731 is a wasteful number, since it uses less digits than its factorization.

21755065551731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5009225461.

The product of its (nonzero) digits is 5512500, while the sum is 53.

The spelling of 21755065551731 in words is "twenty-one trillion, seven hundred fifty-five billion, sixty-five million, five hundred fifty-one thousand, seven hundred thirty-one".