21542612506 has 8 divisors (see below), whose sum is σ = 32449124160. Its totient is φ = 10726237788.

The previous prime is 21542612501. The next prime is 21542612537. The reversal of 21542612506 is 60521624512.

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

It is not an unprimeable number, because it can be changed into a prime (21542612501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22533636 + ... + 22534591.

It is an arithmetic number, because the mean of its divisors is an integer number (4056140520).

Almost surely, 2^21542612506 is an apocalyptic number.

21542612506 is a deficient number, since it is larger than the sum of its proper divisors (10906511654).

21542612506 is a wasteful number, since it uses less digits than its factorization.

21542612506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45068468.

The product of its (nonzero) digits is 28800, while the sum is 34.

The spelling of 21542612506 in words is "twenty-one billion, five hundred forty-two million, six hundred twelve thousand, five hundred six".