21102901654 has 4 divisors (see below), whose sum is σ = 31654352484. Its totient is φ = 10551450826.

The previous prime is 21102901621. The next prime is 21102901667. The reversal of 21102901654 is 45610920112.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5275725412 + ... + 5275725415.

It is an arithmetic number, because the mean of its divisors is an integer number (7913588121).

Almost surely, 2^21102901654 is an apocalyptic number.

21102901654 is a deficient number, since it is larger than the sum of its proper divisors (10551450830).

21102901654 is a wasteful number, since it uses less digits than its factorization.

21102901654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10551450829.

The product of its (nonzero) digits is 4320, while the sum is 31.

The spelling of 21102901654 in words is "twenty-one billion, one hundred two million, nine hundred one thousand, six hundred fifty-four".