21786202338 has 32 divisors (see below), whose sum is σ = 46891820160. Its totient is φ = 6722837760.

The previous prime is 21786202337. The next prime is 21786202343. The reversal of 21786202338 is 83320268712.

It is a super-2 number, since 2×21786202338² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21786202338.

It is not an unprimeable number, because it can be changed into a prime (21786202331) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1744518 + ... + 1756961.

It is an arithmetic number, because the mean of its divisors is an integer number (1465369380).

Almost surely, 2^21786202338 is an apocalyptic number.

21786202338 is an abundant number, since it is smaller than the sum of its proper divisors (25105617822).

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

21786202338 is a wasteful number, since it uses less digits than its factorization.

21786202338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3501562.

The product of its (nonzero) digits is 193536, while the sum is 42.

The spelling of 21786202338 in words is "twenty-one billion, seven hundred eighty-six million, two hundred two thousand, three hundred thirty-eight".