21291131042 has 8 divisors (see below), whose sum is σ = 31938389532. Its totient is φ = 10645001200.

The previous prime is 21291131023. The next prime is 21291131047. The reversal of 21291131042 is 24013119212.

It can be written as a sum of positive squares in 2 ways, for example, as 21021810121 + 269320921 = 144989^2 + 16411^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21291131042² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21291131047) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 233309 + ... + 311472.

Almost surely, 2^21291131042 is an apocalyptic number.

21291131042 is a deficient number, since it is larger than the sum of its proper divisors (10647258490).

21291131042 is a wasteful number, since it uses less digits than its factorization.

21291131042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 564324.

The product of its (nonzero) digits is 864, while the sum is 26.

The spelling of 21291131042 in words is "twenty-one billion, two hundred ninety-one million, one hundred thirty-one thousand, forty-two".