21771421344 has 36 divisors (see below), whose sum is σ = 61912480266. Its totient is φ = 7257140352.

The previous prime is 21771421333. The next prime is 21771421349. The reversal of 21771421344 is 44312417712.

21771421344 is a `hidden beast` number, since 2 + 177 + 142 + 1 + 344 = 666.

It can be written as a sum of positive squares in only one way, i.e., 12053404944 + 9718016400 = 109788^2 + 98580^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a junction number, because it is equal to n+sod(n) for n = 21771421299 and 21771421308.

It is not an unprimeable number, because it can be changed into a prime (21771421349) 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, 37797319 + ... + 37797894.

Almost surely, 2^21771421344 is an apocalyptic number.

21771421344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21771421344 is an abundant number, since it is smaller than the sum of its proper divisors (40141058922).

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

21771421344 is a wasteful number, since it uses less digits than its factorization.

21771421344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75595229 (or 75595218 counting only the distinct ones).

The product of its digits is 37632, while the sum is 36.

The spelling of 21771421344 in words is "twenty-one billion, seven hundred seventy-one million, four hundred twenty-one thousand, three hundred forty-four".