21988954372 has 48 divisors (see below), whose sum is σ = 50500961280. Its totient is φ = 8116221600.

The previous prime is 21988954357. The next prime is 21988954373. The reversal of 21988954372 is 27345988912.

It is a super-2 number, since 2×21988954372² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21988954373) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1872904 + ... + 1884607.

It is an arithmetic number, because the mean of its divisors is an integer number (1052103360).

Almost surely, 2^21988954372 is an apocalyptic number.

21988954372 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21988954372 is an abundant number, since it is smaller than the sum of its proper divisors (28512006908).

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

21988954372 is a wasteful number, since it uses less digits than its factorization.

21988954372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3757552 (or 3757550 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 58.

The spelling of 21988954372 in words is "twenty-one billion, nine hundred eighty-eight million, nine hundred fifty-four thousand, three hundred seventy-two".