21001012131 has 8 divisors (see below), whose sum is σ = 30546926784. Its totient is φ = 12727886120.

The previous prime is 21001012129. The next prime is 21001012147. The reversal of 21001012131 is 13121010012.

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

It is a cyclic number.

It is not a de Polignac number, because 21001012131 - 2¹ = 21001012129 is a prime.

It is a super-2 number, since 2×21001012131² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21001019131) 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, 318197121 + ... + 318197186.

It is an arithmetic number, because the mean of its divisors is an integer number (3818365848).

Almost surely, 2^21001012131 is an apocalyptic number.

21001012131 is a deficient number, since it is larger than the sum of its proper divisors (9545914653).

21001012131 is a wasteful number, since it uses less digits than its factorization.

21001012131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636394321.

The product of its (nonzero) digits is 12, while the sum is 12.

Adding to 21001012131 its reverse (13121010012), we get a palindrome (34122022143).

The spelling of 21001012131 in words is "twenty-one billion, one million, twelve thousand, one hundred thirty-one".