21531513254 has 8 divisors (see below), whose sum is σ = 32610835920. Its totient is φ = 10661234616.

The previous prime is 21531513173. The next prime is 21531513299. The reversal of 21531513254 is 45231513512.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21531513254.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52260749 + ... + 52261160.

It is an arithmetic number, because the mean of its divisors is an integer number (4076354490).

Almost surely, 2^21531513254 is an apocalyptic number.

21531513254 is a deficient number, since it is larger than the sum of its proper divisors (11079322666).

21531513254 is a wasteful number, since it uses less digits than its factorization.

21531513254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104522014.

The product of its digits is 18000, while the sum is 32.

The spelling of 21531513254 in words is "twenty-one billion, five hundred thirty-one million, five hundred thirteen thousand, two hundred fifty-four".