13251997440 has 432 divisors, whose sum is σ = 51706250400. Its totient is φ = 3211591680.

The previous prime is 13251997427. The next prime is 13251997453. The reversal of 13251997440 is 4479915231.

13251997440 is a `hidden beast` number, since 1 + 3 + 2 + 519 + 97 + 4 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (13251997427) and next prime (13251997453).

It is a tau number, because it is divible by the number of its divisors (432).

It is a super-2 number, since 2×13251997440² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4180176 + ... + 4183344.

Almost surely, 2^13251997440 is an apocalyptic number.

13251997440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13251997440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25853125200).

13251997440 is an abundant number, since it is smaller than the sum of its proper divisors (38454252960).

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

13251997440 is a wasteful number, since it uses less digits than its factorization.

13251997440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3221 (or 3190 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The spelling of 13251997440 in words is "thirteen billion, two hundred fifty-one million, nine hundred ninety-seven thousand, four hundred forty".