21897453903 has 16 divisors (see below), whose sum is σ = 31562065920. Its totient is φ = 13424112864.

The previous prime is 21897453869. The next prime is 21897453931. The reversal of 21897453903 is 30935479812.

It is not a de Polignac number, because 21897453903 - 2⁶ = 21897453839 is a prime.

It is a super-3 number, since 3×21897453903³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21897453983) 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, 1057183 + ... + 1077696.

It is an arithmetic number, because the mean of its divisors is an integer number (1972629120).

Almost surely, 2^21897453903 is an apocalyptic number.

21897453903 is a deficient number, since it is larger than the sum of its proper divisors (9664612017).

21897453903 is a wasteful number, since it uses less digits than its factorization.

21897453903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2135158.

The product of its (nonzero) digits is 1632960, while the sum is 51.

It can be divided in two parts, 21897 and 453903, that added together give a triangular number (475800 = T₉₇₅).

The spelling of 21897453903 in words is "twenty-one billion, eight hundred ninety-seven million, four hundred fifty-three thousand, nine hundred three".