21989173760 has 40 divisors (see below), whose sum is σ = 52722486036. Its totient is φ = 8795668480.

The previous prime is 21989173747. The next prime is 21989173777. The reversal of 21989173760 is 6737198912.

It can be written as a sum of positive squares in 2 ways, for example, as 21073748224 + 915425536 = 145168^2 + 30256^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4292201 + ... + 4297320.

Almost surely, 2^21989173760 is an apocalyptic number.

21989173760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21989173760 is an abundant number, since it is smaller than the sum of its proper divisors (30733312276).

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

21989173760 is an frugal number, since it uses more digits than its factorization.

21989173760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8589544 (or 8589528 counting only the distinct ones).

The product of its (nonzero) digits is 1143072, while the sum is 53.

The spelling of 21989173760 in words is "twenty-one billion, nine hundred eighty-nine million, one hundred seventy-three thousand, seven hundred sixty".