21861399112308 has 72 divisors (see below), whose sum is σ = 65931203688000. Its totient is φ = 6246114030576.

The previous prime is 21861399112303. The next prime is 21861399112361. The reversal of 21861399112308 is 80321199316812.

It is a happy number.

21861399112308 is a `hidden beast` number, since 2 + 1 + 8 + 6 + 1 + 399 + 11 + 230 + 8 = 666.

It is a super-4 number, since 4×21861399112308⁴ (a number of 54 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21861399112303) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2065508608 + ... + 2065519191.

Almost surely, 2^{21861399112308} is an apocalyptic number.

21861399112308 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21861399112308 is an abundant number, since it is smaller than the sum of its proper divisors (44069804575692).

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

21861399112308 is a wasteful number, since it uses less digits than its factorization.

21861399112308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4131027826 (or 4131027811 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The spelling of 21861399112308 in words is "twenty-one trillion, eight hundred sixty-one billion, three hundred ninety-nine million, one hundred twelve thousand, three hundred eight".