21531658159 has 32 divisors (see below), whose sum is σ = 26424014400. Its totient is φ = 17306634240.

The previous prime is 21531658157. The next prime is 21531658171. The reversal of 21531658159 is 95185613512.

It is a cyclic number.

It is not a de Polignac number, because 21531658159 - 2¹ = 21531658157 is a prime.

It is a super-2 number, since 2×21531658159² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531658151) 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, 146997 + ... + 254305.

It is an arithmetic number, because the mean of its divisors is an integer number (825750450).

Almost surely, 2^21531658159 is an apocalyptic number.

21531658159 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21531658159 is a deficient number, since it is larger than the sum of its proper divisors (4892356241).

21531658159 is a wasteful number, since it uses less digits than its factorization.

21531658159 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107403.

The product of its digits is 324000, while the sum is 46.

The spelling of 21531658159 in words is "twenty-one billion, five hundred thirty-one million, six hundred fifty-eight thousand, one hundred fifty-nine".