21787494810 has 16 divisors (see below), whose sum is σ = 52289987616. Its totient is φ = 5809998608.

The previous prime is 21787494787. The next prime is 21787494811. The reversal of 21787494810 is 1849478712.

21787494810 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×21787494810² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21787494811) 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, 363124884 + ... + 363124943.

It is an arithmetic number, because the mean of its divisors is an integer number (3268124226).

Almost surely, 2^21787494810 is an apocalyptic number.

21787494810 is an abundant number, since it is smaller than the sum of its proper divisors (30502492806).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21787494810 is a wasteful number, since it uses less digits than its factorization.

21787494810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 726249837.

The product of its (nonzero) digits is 903168, while the sum is 51.

The spelling of 21787494810 in words is "twenty-one billion, seven hundred eighty-seven million, four hundred ninety-four thousand, eight hundred ten".