21542472961 has 8 divisors (see below), whose sum is σ = 22005787104. Its totient is φ = 21084010560.

The previous prime is 21542472953. The next prime is 21542472971. The reversal of 21542472961 is 16927424512.

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 21542472961 - 2³ = 21542472953 is a prime.

It is a super-2 number, since 2×21542472961² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21542472971) 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, 1203960 + ... + 1221721.

It is an arithmetic number, because the mean of its divisors is an integer number (2750723388).

Almost surely, 2^21542472961 is an apocalyptic number.

It is an amenable number.

21542472961 is a deficient number, since it is larger than the sum of its proper divisors (463314143).

21542472961 is a wasteful number, since it uses less digits than its factorization.

21542472961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2425871.

The product of its digits is 241920, while the sum is 43.

The spelling of 21542472961 in words is "twenty-one billion, five hundred forty-two million, four hundred seventy-two thousand, nine hundred sixty-one".