21981541092 has 24 divisors (see below), whose sum is σ = 58617443136. Its totient is φ = 6280440288.

The previous prime is 21981541081. The next prime is 21981541103. The reversal of 21981541092 is 29014518912.

It is an interprime number because it is at equal distance from previous prime (21981541081) and next prime (21981541103).

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 130842423 + ... + 130842590.

It is an arithmetic number, because the mean of its divisors is an integer number (2442393464).

Almost surely, 2^21981541092 is an apocalyptic number.

It is an amenable number.

21981541092 is an abundant number, since it is smaller than the sum of its proper divisors (36635902044).

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

21981541092 is a wasteful number, since it uses less digits than its factorization.

21981541092 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261685027 (or 261685025 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 42.

The spelling of 21981541092 in words is "twenty-one billion, nine hundred eighty-one million, five hundred forty-one thousand, ninety-two".