21402389980 has 24 divisors (see below), whose sum is σ = 44963715888. Its totient is φ = 8557394688.

The previous prime is 21402389977. The next prime is 21402390029. The reversal of 21402389980 is 8998320412.

It is a self number, because there is not a number n which added to its sum of digits gives 21402389980.

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, 173034 + ... + 269713.

It is an arithmetic number, because the mean of its divisors is an integer number (1873488162).

Almost surely, 2^21402389980 is an apocalyptic number.

21402389980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21402389980 is an abundant number, since it is smaller than the sum of its proper divisors (23561325908).

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

21402389980 is a wasteful number, since it uses less digits than its factorization.

21402389980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445173 (or 445171 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 46.

The spelling of 21402389980 in words is "twenty-one billion, four hundred two million, three hundred eighty-nine thousand, nine hundred eighty".