21671981274 has 16 divisors (see below), whose sum is σ = 43347569760. Its totient is φ = 7223392560.

The previous prime is 21671981273. The next prime is 21671981297. The reversal of 21671981274 is 47218917612.

It is not an unprimeable number, because it can be changed into a prime (21671981273) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68797 + ... + 219264.

It is an arithmetic number, because the mean of its divisors is an integer number (2709223110).

Almost surely, 2^21671981274 is an apocalyptic number.

21671981274 is an abundant number, since it is smaller than the sum of its proper divisors (21675588486).

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

21671981274 is a wasteful number, since it uses less digits than its factorization.

21671981274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 300605.

The product of its digits is 338688, while the sum is 48.

The spelling of 21671981274 in words is "twenty-one billion, six hundred seventy-one million, nine hundred eighty-one thousand, two hundred seventy-four".