21001022031 has 16 divisors (see below), whose sum is σ = 32154675840. Its totient is φ = 12058002720.

The previous prime is 21001021991. The next prime is 21001022033. The reversal of 21001022031 is 13022010012.

It is not a de Polignac number, because 21001022031 - 2⁷ = 21001021903 is a prime.

It is a super-2 number, since 2×21001022031² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21001021998 and 21001022016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001022033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16746600 + ... + 16747853.

It is an arithmetic number, because the mean of its divisors is an integer number (2009667240).

Almost surely, 2^21001022031 is an apocalyptic number.

21001022031 is a deficient number, since it is larger than the sum of its proper divisors (11153653809).

21001022031 is a wasteful number, since it uses less digits than its factorization.

21001022031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33494486.

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21001022031 its reverse (13022010012), we get a palindrome (34023032043).

The spelling of 21001022031 in words is "twenty-one billion, one million, twenty-two thousand, thirty-one".