21859144290 has 24 divisors (see below), whose sum is σ = 56833775388. Its totient is φ = 5829105120.

The previous prime is 21859144273. The next prime is 21859144327. The reversal of 21859144290 is 9244195812.

It is a happy number.

21859144290 is a `hidden beast` number, since 2 + 18 + 591 + 4 + 42 + 9 + 0 = 666.

21859144290 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 18347515209 + 3511629081 = 135453^2 + 59259^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 121439601 + ... + 121439780.

Almost surely, 2^21859144290 is an apocalyptic number.

21859144290 is an abundant number, since it is smaller than the sum of its proper divisors (34974631098).

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

21859144290 is a wasteful number, since it uses less digits than its factorization.

21859144290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242879394 (or 242879391 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The spelling of 21859144290 in words is "twenty-one billion, eight hundred fifty-nine million, one hundred forty-four thousand, two hundred ninety".