21489756174 has 24 divisors (see below), whose sum is σ = 46567775592. Its totient is φ = 7162230960.

The previous prime is 21489756161. The next prime is 21489756179. The reversal of 21489756174 is 47165798412.

21489756174 is a `hidden beast` number, since 2 + 1 + 4 + 8 + 9 + 7 + 561 + 74 = 666.

It is a super-2 number, since 2×21489756174² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21489756174.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21489756179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 50532 + ... + 213384.

It is an arithmetic number, because the mean of its divisors is an integer number (1940323983).

Almost surely, 2^21489756174 is an apocalyptic number.

21489756174 is an abundant number, since it is smaller than the sum of its proper divisors (25078019418).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21489756174 is a wasteful number, since it uses less digits than its factorization.

21489756174 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170192 (or 170189 counting only the distinct ones).

The product of its digits is 3386880, while the sum is 54.

The spelling of 21489756174 in words is "twenty-one billion, four hundred eighty-nine million, seven hundred fifty-six thousand, one hundred seventy-four".