21401554028 has 24 divisors (see below), whose sum is σ = 38085114480. Its totient is φ = 10520262720.

The previous prime is 21401554007. The next prime is 21401554087. The reversal of 21401554028 is 82045510412.

It is a junction number, because it is equal to n+sod(n) for n = 21401553985 and 21401554003.

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 in 7 ways as a sum of consecutive naturals, for example, 511550 + ... + 551802.

It is an arithmetic number, because the mean of its divisors is an integer number (1586879770).

Almost surely, 2^21401554028 is an apocalyptic number.

It is an amenable number.

21401554028 is a deficient number, since it is larger than the sum of its proper divisors (16683560452).

21401554028 is a wasteful number, since it uses less digits than its factorization.

21401554028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42497 (or 42495 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 32.

The spelling of 21401554028 in words is "twenty-one billion, four hundred one million, five hundred fifty-four thousand, twenty-eight".