21790199660 has 24 divisors (see below), whose sum is σ = 45778721856. Its totient is φ = 8712403200.

The previous prime is 21790199659. The next prime is 21790199693. The reversal of 21790199660 is 6699109712.

It is a junction number, because it is equal to n+sod(n) for n = 21790199599 and 21790199608.

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, 180941 + ... + 276260.

It is an arithmetic number, because the mean of its divisors is an integer number (1907446744).

Almost surely, 2^21790199660 is an apocalyptic number.

21790199660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21790199660 is an abundant number, since it is smaller than the sum of its proper divisors (23988522196).

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

21790199660 is a wasteful number, since it uses less digits than its factorization.

21790199660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459593 (or 459591 counting only the distinct ones).

The product of its (nonzero) digits is 367416, while the sum is 50.

The spelling of 21790199660 in words is "twenty-one billion, seven hundred ninety million, one hundred ninety-nine thousand, six hundred sixty".