21357495087889 has 9 divisors (see below), whose sum is σ = 21378686798473. Its totient is φ = 21336324376612.

The previous prime is 21357495087883. The next prime is 21357495087913. The reversal of 21357495087889 is 98878059475312.

The square root of 21357495087889 is 4621417.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 21357495087889 - 2¹¹ = 21357495085841 is a prime.

It is a super-2 number, since 2×21357495087889² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21357495087883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 6927502542 + ... + 6927505624.

Almost surely, 2^{21357495087889} is an apocalyptic number.

21357495087889 is the 4621417-th square number.

21357495087889 is the 2310709-th centered octagonal number.

It is an amenable number.

21357495087889 is a deficient number, since it is larger than the sum of its proper divisors (21191710584).

21357495087889 is an frugal number, since it uses more digits than its factorization.

21357495087889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9164 (or 4582 counting only the distinct ones).

The product of its (nonzero) digits is 1219276800, while the sum is 76.

The spelling of 21357495087889 in words is "twenty-one trillion, three hundred fifty-seven billion, four hundred ninety-five million, eighty-seven thousand, eight hundred eighty-nine".