21820149504 has 54 divisors (see below), whose sum is σ = 62912876936. Its totient is φ = 7273382400.

The previous prime is 21820149503. The next prime is 21820149511. The reversal of 21820149504 is 40594102812.

21820149504 is a `hidden beast` number, since 2 + 1 + 8 + 2 + 0 + 149 + 504 = 666.

It is a super-3 number, since 3×21820149504³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21820149503) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4732972 + ... + 4737579.

Almost surely, 2^21820149504 is an apocalyptic number.

21820149504 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21820149504 is an abundant number, since it is smaller than the sum of its proper divisors (41092727432).

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

21820149504 is an equidigital number, since it uses as much as digits as its factorization.

21820149504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9470573 (or 9470556 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The spelling of 21820149504 in words is "twenty-one billion, eight hundred twenty million, one hundred forty-nine thousand, five hundred four".