21548396940 has 48 divisors (see below), whose sum is σ = 68954871552. Its totient is φ = 4925347776.

The previous prime is 21548396923. The next prime is 21548396941. The reversal of 21548396940 is 4969384512.

It is not an unprimeable number, because it can be changed into a prime (21548396941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25652434 + ... + 25653273.

It is an arithmetic number, because the mean of its divisors is an integer number (1436559824).

Almost surely, 2^21548396940 is an apocalyptic number.

21548396940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21548396940 is an abundant number, since it is smaller than the sum of its proper divisors (47406474612).

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

21548396940 is a wasteful number, since it uses less digits than its factorization.

21548396940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51305726 (or 51305724 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 51.

The spelling of 21548396940 in words is "twenty-one billion, five hundred forty-eight million, three hundred ninety-six thousand, nine hundred forty".