21368073390 has 64 divisors (see below), whose sum is σ = 53189056512. Its totient is φ = 5488156800.

The previous prime is 21368073329. The next prime is 21368073401. The reversal of 21368073390 is 9337086312.

It is a happy number.

It is a super-3 number, since 3×21368073390³ (a number of 32 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 141784 + ... + 250676.

It is an arithmetic number, because the mean of its divisors is an integer number (831079008).

Almost surely, 2^21368073390 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21368073390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26594528256).

21368073390 is an abundant number, since it is smaller than the sum of its proper divisors (31820983122).

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

21368073390 is a wasteful number, since it uses less digits than its factorization.

21368073390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109145.

The product of its (nonzero) digits is 163296, while the sum is 42.

The spelling of 21368073390 in words is "twenty-one billion, three hundred sixty-eight million, seventy-three thousand, three hundred ninety".