21959528645 has 16 divisors (see below), whose sum is σ = 27557383680. Its totient is φ = 16767003264.

The previous prime is 21959528639. The next prime is 21959528651. The reversal of 21959528645 is 54682595912.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21959528639) and next prime (21959528651).

It is a cyclic number.

It is not a de Polignac number, because 21959528645 - 2⁴ = 21959528629 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 156365 + ... + 261474.

It is an arithmetic number, because the mean of its divisors is an integer number (1722336480).

Almost surely, 2^21959528645 is an apocalyptic number.

It is an amenable number.

21959528645 is a deficient number, since it is larger than the sum of its proper divisors (5597855035).

21959528645 is a wasteful number, since it uses less digits than its factorization.

21959528645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418324.

The product of its digits is 7776000, while the sum is 56.

The spelling of 21959528645 in words is "twenty-one billion, nine hundred fifty-nine million, five hundred twenty-eight thousand, six hundred forty-five".