21158588549 has 16 divisors (see below), whose sum is σ = 24311734272. Its totient is φ = 18038215728.

The previous prime is 21158588531. The next prime is 21158588551. The reversal of 21158588549 is 94588585112.

It is a cyclic number.

It is not a de Polignac number, because 21158588549 - 2²⁰ = 21157539973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21158588494 and 21158588503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21158588509) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1903562 + ... + 1914644.

It is an arithmetic number, because the mean of its divisors is an integer number (1519483392).

Almost surely, 2^21158588549 is an apocalyptic number.

It is an amenable number.

21158588549 is a deficient number, since it is larger than the sum of its proper divisors (3153145723).

21158588549 is a wasteful number, since it uses less digits than its factorization.

21158588549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12536.

The product of its digits is 4608000, while the sum is 56.

The spelling of 21158588549 in words is "twenty-one billion, one hundred fifty-eight million, five hundred eighty-eight thousand, five hundred forty-nine".