21390575089 has 8 divisors (see below), whose sum is σ = 23054465000. Its totient is φ = 19729322496.

The previous prime is 21390575077. The next prime is 21390575099. The reversal of 21390575089 is 98057509312.

It can be written as a sum of positive squares in 4 ways, for example, as 418611600 + 20971963489 = 20460^2 + 144817^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21390575089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21390575009) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 642462 + ... + 674935.

It is an arithmetic number, because the mean of its divisors is an integer number (2881808125).

Almost surely, 2^21390575089 is an apocalyptic number.

It is an amenable number.

21390575089 is a deficient number, since it is larger than the sum of its proper divisors (1663889911).

21390575089 is a wasteful number, since it uses less digits than its factorization.

21390575089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1318659.

The product of its (nonzero) digits is 680400, while the sum is 49.

The spelling of 21390575089 in words is "twenty-one billion, three hundred ninety million, five hundred seventy-five thousand, eighty-nine".