21397366367 has 4 divisors (see below), whose sum is σ = 23043317640. Its totient is φ = 19751415096.

The previous prime is 21397366343. The next prime is 21397366373. The reversal of 21397366367 is 76366379312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21397366367 - 2¹⁰ = 21397365343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21397366337) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 822975617 + ... + 822975642.

It is an arithmetic number, because the mean of its divisors is an integer number (5760829410).

Almost surely, 2^21397366367 is an apocalyptic number.

21397366367 is a deficient number, since it is larger than the sum of its proper divisors (1645951273).

21397366367 is a wasteful number, since it uses less digits than its factorization.

21397366367 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1645951272.

The product of its digits is 5143824, while the sum is 53.

The spelling of 21397366367 in words is "twenty-one billion, three hundred ninety-seven million, three hundred sixty-six thousand, three hundred sixty-seven".