21401504988 has 24 divisors (see below), whose sum is σ = 50011064208. Its totient is φ = 7123232256.

The previous prime is 21401504983. The next prime is 21401505023. The reversal of 21401504988 is 88940510412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21401504983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1316931 + ... + 1333082.

It is an arithmetic number, because the mean of its divisors is an integer number (2083794342).

Almost surely, 2^21401504988 is an apocalyptic number.

It is an amenable number.

21401504988 is an abundant number, since it is smaller than the sum of its proper divisors (28609559220).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21401504988 is a wasteful number, since it uses less digits than its factorization.

21401504988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2650693 (or 2650691 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 42.

The spelling of 21401504988 in words is "twenty-one billion, four hundred one million, five hundred four thousand, nine hundred eighty-eight".