21185066654 has 16 divisors (see below), whose sum is σ = 31821431040. Its totient is φ = 10577936280.

The previous prime is 21185066611. The next prime is 21185066687. The reversal of 21185066654 is 45666058112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7965977 + ... + 7968635.

It is an arithmetic number, because the mean of its divisors is an integer number (1988839440).

Almost surely, 2^21185066654 is an apocalyptic number.

21185066654 is a deficient number, since it is larger than the sum of its proper divisors (10636364386).

21185066654 is a wasteful number, since it uses less digits than its factorization.

21185066654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6655.

The product of its (nonzero) digits is 345600, while the sum is 44.

The spelling of 21185066654 in words is "twenty-one billion, one hundred eighty-five million, sixty-six thousand, six hundred fifty-four".