21203023431 has 16 divisors (see below), whose sum is σ = 29253339360. Its totient is φ = 13644288000.

The previous prime is 21203023423. The next prime is 21203023451. The reversal of 21203023431 is 13432030212.

It is not a de Polignac number, because 21203023431 - 2³ = 21203023423 is a prime.

It is a super-2 number, since 2×21203023431² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21203023398 and 21203023407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203023451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 317631 + ... + 378543.

It is an arithmetic number, because the mean of its divisors is an integer number (1828333710).

Almost surely, 2^21203023431 is an apocalyptic number.

21203023431 is a deficient number, since it is larger than the sum of its proper divisors (8050315929).

21203023431 is a wasteful number, since it uses less digits than its factorization.

21203023431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64946.

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21203023431 its reverse (13432030212), we get a palindrome (34635053643).

The spelling of 21203023431 in words is "twenty-one billion, two hundred three million, twenty-three thousand, four hundred thirty-one".