21947831754 has 16 divisors (see below), whose sum is σ = 45082033248. Its totient is φ = 7118215632.

The previous prime is 21947831753. The next prime is 21947831777. The reversal of 21947831754 is 45713874912.

It is a junction number, because it is equal to n+sod(n) for n = 21947831697 and 21947831706.

It is not an unprimeable number, because it can be changed into a prime (21947831753) 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, 49431832 + ... + 49432275.

It is an arithmetic number, because the mean of its divisors is an integer number (2817627078).

Almost surely, 2^21947831754 is an apocalyptic number.

21947831754 is an abundant number, since it is smaller than the sum of its proper divisors (23134201494).

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

21947831754 is a wasteful number, since it uses less digits than its factorization.

21947831754 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98864149.

The product of its digits is 1693440, while the sum is 51.

The spelling of 21947831754 in words is "twenty-one billion, nine hundred forty-seven million, eight hundred thirty-one thousand, seven hundred fifty-four".