21368609390 has 16 divisors (see below), whose sum is σ = 38844325440. Its totient is φ = 8462815200.

The previous prime is 21368609363. The next prime is 21368609441. The reversal of 21368609390 is 9390686312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10577510 + ... + 10579529.

It is an arithmetic number, because the mean of its divisors is an integer number (2427770340).

Almost surely, 2^21368609390 is an apocalyptic number.

21368609390 is a deficient number, since it is larger than the sum of its proper divisors (17475716050).

21368609390 is a wasteful number, since it uses less digits than its factorization.

21368609390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21157147.

The product of its (nonzero) digits is 419904, while the sum is 47.

The spelling of 21368609390 in words is "twenty-one billion, three hundred sixty-eight million, six hundred nine thousand, three hundred ninety".