21015224002531 has 12 divisors (see below), whose sum is σ = 23895908744400. Its totient is φ = 18445964638640.

The previous prime is 21015224002489. The next prime is 21015224002547. The reversal of 21015224002531 is 13520042251012.

It is a happy number.

It is not a de Polignac number, because 21015224002531 - 2⁴¹ = 18816200746979 is a prime.

It is a super-2 number, since 2×21015224002531² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21015224002531.

It is not an unprimeable number, because it can be changed into a prime (21015224002231) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2994471271 + ... + 2994478288.

It is an arithmetic number, because the mean of its divisors is an integer number (1991325728700).

Almost surely, 2^{21015224002531} is an apocalyptic number.

21015224002531 is a deficient number, since it is larger than the sum of its proper divisors (2880684741869).

21015224002531 is a wasteful number, since it uses less digits than its factorization.

21015224002531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5988949610 (or 5988949599 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

Adding to 21015224002531 its reverse (13520042251012), we get a palindrome (34535266253543).

The spelling of 21015224002531 in words is "twenty-one trillion, fifteen billion, two hundred twenty-four million, two thousand, five hundred thirty-one".