21958305609 has 16 divisors (see below), whose sum is σ = 30792420864. Its totient is φ = 13899350400.

The previous prime is 21958305601. The next prime is 21958305613. The reversal of 21958305609 is 90650385912.

It is a happy number.

It is not a de Polignac number, because 21958305609 - 2³ = 21958305601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21958305601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2222532 + ... + 2232389.

It is an arithmetic number, because the mean of its divisors is an integer number (1924526304).

Almost surely, 2^21958305609 is an apocalyptic number.

It is an amenable number.

21958305609 is a deficient number, since it is larger than the sum of its proper divisors (8834115255).

21958305609 is a wasteful number, since it uses less digits than its factorization.

21958305609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4455008.

The product of its (nonzero) digits is 583200, while the sum is 48.

The spelling of 21958305609 in words is "twenty-one billion, nine hundred fifty-eight million, three hundred five thousand, six hundred nine".