21990453593 has 4 divisors (see below), whose sum is σ = 22136085888. Its totient is φ = 21844821300.

The previous prime is 21990453559. The next prime is 21990453637. The reversal of 21990453593 is 39535409912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21990453593 - 2⁸ = 21990453337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21990453523) 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, 72815921 + ... + 72816222.

It is an arithmetic number, because the mean of its divisors is an integer number (5534021472).

Almost surely, 2^21990453593 is an apocalyptic number.

It is an amenable number.

21990453593 is a deficient number, since it is larger than the sum of its proper divisors (145632295).

21990453593 is a wasteful number, since it uses less digits than its factorization.

21990453593 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145632294.

The product of its (nonzero) digits is 1312200, while the sum is 50.

The spelling of 21990453593 in words is "twenty-one billion, nine hundred ninety million, four hundred fifty-three thousand, five hundred ninety-three".