21231202511 has 8 divisors (see below), whose sum is σ = 21759561984. Its totient is φ = 20706036120.

The previous prime is 21231202481. The next prime is 21231202529. The reversal of 21231202511 is 11520213212.

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

It is a de Polignac number, because none of the positive numbers 2^k-21231202511 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231232511) 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, 784805 + ... + 811406.

It is an arithmetic number, because the mean of its divisors is an integer number (2719945248).

Almost surely, 2^21231202511 is an apocalyptic number.

21231202511 is a deficient number, since it is larger than the sum of its proper divisors (528359473).

21231202511 is a wasteful number, since it uses less digits than its factorization.

21231202511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1596541.

The product of its (nonzero) digits is 240, while the sum is 20.

Adding to 21231202511 its reverse (11520213212), we get a palindrome (32751415723).

The spelling of 21231202511 in words is "twenty-one billion, two hundred thirty-one million, two hundred two thousand, five hundred eleven".