21153591571 has 32 divisors (see below), whose sum is σ = 24752609280. Its totient is φ = 17704832256.

The previous prime is 21153591509. The next prime is 21153591583. The reversal of 21153591571 is 17519535112.

It is a cyclic number.

It is not a de Polignac number, because 21153591571 - 2¹⁹ = 21153067283 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21153591971) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 41558865 + ... + 41559373.

It is an arithmetic number, because the mean of its divisors is an integer number (773519040).

Almost surely, 2^21153591571 is an apocalyptic number.

21153591571 is a deficient number, since it is larger than the sum of its proper divisors (3599017709).

21153591571 is a wasteful number, since it uses less digits than its factorization.

21153591571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1243.

The product of its digits is 47250, while the sum is 40.

The spelling of 21153591571 in words is "twenty-one billion, one hundred fifty-three million, five hundred ninety-one thousand, five hundred seventy-one".