21326549660 has 24 divisors (see below), whose sum is σ = 48230812896. Its totient is φ = 7874418240.

The previous prime is 21326549633. The next prime is 21326549683. The reversal of 21326549660 is 6694562312.

It is a super-2 number, since 2×21326549660² (a number of 21 digits) contains 22 as substring.

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, 41012336 + ... + 41012855.

It is an arithmetic number, because the mean of its divisors is an integer number (2009617204).

Almost surely, 2^21326549660 is an apocalyptic number.

21326549660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21326549660 is an abundant number, since it is smaller than the sum of its proper divisors (26904263236).

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

21326549660 is a wasteful number, since it uses less digits than its factorization.

21326549660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82025213 (or 82025211 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 44.

The spelling of 21326549660 in words is "twenty-one billion, three hundred twenty-six million, five hundred forty-nine thousand, six hundred sixty".