21518654 has 4 divisors (see below), whose sum is σ = 32277984. Its totient is φ = 10759326.

The previous prime is 21518647. The next prime is 21518669. The reversal of 21518654 is 45681512.

It is a semiprime because it is the product of two primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21518654.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5379662 + ... + 5379665.

It is an arithmetic number, because the mean of its divisors is an integer number (8069496).

Almost surely, 2^21518654 is an apocalyptic number.

21518654 is a deficient number, since it is larger than the sum of its proper divisors (10759330).

21518654 is a wasteful number, since it uses less digits than its factorization.

21518654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10759329.

The product of its digits is 9600, while the sum is 32.

The square root of 21518654 is about 4638.8203241773. The cubic root of 21518654 is about 278.1452840317.

The spelling of 21518654 in words is "twenty-one million, five hundred eighteen thousand, six hundred fifty-four".