21958384523 has 4 divisors (see below), whose sum is σ = 22118664840. Its totient is φ = 21798104208.

The previous prime is 21958384519. The next prime is 21958384571. The reversal of 21958384523 is 32548385912.

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 21958384523 - 2² = 21958384519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21958384223) 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, 80139953 + ... + 80140226.

It is an arithmetic number, because the mean of its divisors is an integer number (5529666210).

Almost surely, 2^21958384523 is an apocalyptic number.

21958384523 is a deficient number, since it is larger than the sum of its proper divisors (160280317).

21958384523 is a wasteful number, since it uses less digits than its factorization.

21958384523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160280316.

The product of its digits is 2073600, while the sum is 50.

The spelling of 21958384523 in words is "twenty-one billion, nine hundred fifty-eight million, three hundred eighty-four thousand, five hundred twenty-three".