21952531442 has 4 divisors (see below), whose sum is σ = 32928797166. Its totient is φ = 10976265720.

The previous prime is 21952531427. The next prime is 21952531463. The reversal of 21952531442 is 24413525912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 14160762001 + 7791769441 = 118999^2 + 88271^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21952531396 and 21952531405.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5488132859 + ... + 5488132862.

Almost surely, 2^21952531442 is an apocalyptic number.

21952531442 is a deficient number, since it is larger than the sum of its proper divisors (10976265724).

21952531442 is a wasteful number, since it uses less digits than its factorization.

21952531442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10976265723.

The product of its digits is 86400, while the sum is 38.

The spelling of 21952531442 in words is "twenty-one billion, nine hundred fifty-two million, five hundred thirty-one thousand, four hundred forty-two".