21970531100 has 144 divisors (see below), whose sum is σ = 55886423040. Its totient is φ = 7341734400.

The previous prime is 21970531091. The next prime is 21970531147. The reversal of 21970531100 is 113507912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4420817 + ... + 4425783.

It is an arithmetic number, because the mean of its divisors is an integer number (388100160).

Almost surely, 2^21970531100 is an apocalyptic number.

21970531100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21970531100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27943211520).

21970531100 is an abundant number, since it is smaller than the sum of its proper divisors (33915891940).

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

21970531100 is a wasteful number, since it uses less digits than its factorization.

21970531100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5148 (or 5141 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 29.

The spelling of 21970531100 in words is "twenty-one billion, nine hundred seventy million, five hundred thirty-one thousand, one hundred".