21466657731 has 8 divisors (see below), whose sum is σ = 28643915520. Its totient is φ = 14300252552.

The previous prime is 21466657721. The next prime is 21466657769. The reversal of 21466657731 is 13775666412.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21466657731 - 2⁷ = 21466657603 is a prime.

It is a super-2 number, since 2×21466657731² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21466657711) 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, 2708535 + ... + 2716448.

It is an arithmetic number, because the mean of its divisors is an integer number (3580489440).

Almost surely, 2^21466657731 is an apocalyptic number.

21466657731 is a deficient number, since it is larger than the sum of its proper divisors (7177257789).

21466657731 is a wasteful number, since it uses less digits than its factorization.

21466657731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5426305.

The product of its digits is 1270080, while the sum is 48.

The spelling of 21466657731 in words is "twenty-one billion, four hundred sixty-six million, six hundred fifty-seven thousand, seven hundred thirty-one".