20440431021 has 32 divisors (see below), whose sum is σ = 29983766400. Its totient is φ = 12335984640.

The previous prime is 20440430987. The next prime is 20440431041. The reversal of 20440431021 is 12013404402.

It is not a de Polignac number, because 20440431021 - 2⁶ = 20440430957 is a prime.

It is a super-2 number, since 2×20440431021² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20440431041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 96601 + ... + 224081.

It is an arithmetic number, because the mean of its divisors is an integer number (936992700).

Almost surely, 2^20440431021 is an apocalyptic number.

It is an amenable number.

20440431021 is a deficient number, since it is larger than the sum of its proper divisors (9543335379).

20440431021 is a wasteful number, since it uses less digits than its factorization.

20440431021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127629.

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 20440431021 its reverse (12013404402), we get a palindrome (32453835423).

The spelling of 20440431021 in words is "twenty billion, four hundred forty million, four hundred thirty-one thousand, twenty-one".