21406006580 has 48 divisors (see below), whose sum is σ = 51569844480. Its totient is φ = 7311283968.

The previous prime is 21406006549. The next prime is 21406006607. The reversal of 21406006580 is 8560060412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 253865 + ... + 327504.

It is an arithmetic number, because the mean of its divisors is an integer number (1074371760).

Almost surely, 2^21406006580 is an apocalyptic number.

21406006580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21406006580 is an abundant number, since it is smaller than the sum of its proper divisors (30163837900).

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

21406006580 is a wasteful number, since it uses less digits than its factorization.

21406006580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 581648 (or 581646 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

Adding to 21406006580 its reverse (8560060412), we get a palindrome (29966066992).

The spelling of 21406006580 in words is "twenty-one billion, four hundred six million, six thousand, five hundred eighty".