21495015654 has 32 divisors (see below), whose sum is σ = 51267617280. Its totient is φ = 5874413952.

The previous prime is 21495015599. The next prime is 21495015667. The reversal of 21495015654 is 45651059412.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11124819 + ... + 11126750.

It is an arithmetic number, because the mean of its divisors is an integer number (1602113040).

Almost surely, 2^21495015654 is an apocalyptic number.

21495015654 is an abundant number, since it is smaller than the sum of its proper divisors (29772601626).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21495015654 is a wasteful number, since it uses less digits than its factorization.

21495015654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22251604.

The product of its (nonzero) digits is 216000, while the sum is 42.

The spelling of 21495015654 in words is "twenty-one billion, four hundred ninety-five million, fifteen thousand, six hundred fifty-four".