21536356945 has 8 divisors (see below), whose sum is σ = 25850226240. Its totient is φ = 17224686960.

The previous prime is 21536356903. The next prime is 21536356991. The reversal of 21536356945 is 54965363512.

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

It is not a de Polignac number, because 21536356945 - 2⁷ = 21536356817 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 528205 + ... + 567514.

It is an arithmetic number, because the mean of its divisors is an integer number (3231278280).

Almost surely, 2^21536356945 is an apocalyptic number.

It is an amenable number.

21536356945 is a deficient number, since it is larger than the sum of its proper divisors (4313869295).

21536356945 is a wasteful number, since it uses less digits than its factorization.

21536356945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1099655.

The product of its digits is 2916000, while the sum is 49.

The spelling of 21536356945 in words is "twenty-one billion, five hundred thirty-six million, three hundred fifty-six thousand, nine hundred forty-five".