21002021131 has 16 divisors (see below), whose sum is σ = 25852345344. Its totient is φ = 16614602784.

The previous prime is 21002021123. The next prime is 21002021147. The reversal of 21002021131 is 13112020012.

It is not a de Polignac number, because 21002021131 - 2³ = 21002021123 is a prime.

It is a super-2 number, since 2×21002021131² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is not an unprimeable number, because it can be changed into a prime (21002081131) 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, 899106 + ... + 922168.

It is an arithmetic number, because the mean of its divisors is an integer number (1615771584).

Almost surely, 2^21002021131 is an apocalyptic number.

21002021131 is a deficient number, since it is larger than the sum of its proper divisors (4850324213).

21002021131 is a wasteful number, since it uses less digits than its factorization.

21002021131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33090.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21002021131 its reverse (13112020012), we get a palindrome (34114041143).

The spelling of 21002021131 in words is "twenty-one billion, two million, twenty-one thousand, one hundred thirty-one".