21304542131 has 4 divisors (see below), whose sum is σ = 21317784600. Its totient is φ = 21291299664.

The previous prime is 21304542121. The next prime is 21304542163. The reversal of 21304542131 is 13124540312.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21304542131 - 2⁶ = 21304542067 is a prime.

It is a super-2 number, since 2×21304542131² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21304542131.

It is not an unprimeable number, because it can be changed into a prime (21304542121) 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, 6618821 + ... + 6622038.

It is an arithmetic number, because the mean of its divisors is an integer number (5329446150).

Almost surely, 2^21304542131 is an apocalyptic number.

21304542131 is a deficient number, since it is larger than the sum of its proper divisors (13242469).

21304542131 is a wasteful number, since it uses less digits than its factorization.

21304542131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13242468.

The product of its (nonzero) digits is 2880, while the sum is 26.

The spelling of 21304542131 in words is "twenty-one billion, three hundred four million, five hundred forty-two thousand, one hundred thirty-one".