1251513648 has 360 divisors, whose sum is σ = 4555486208. Its totient is φ = 313632000.

The previous prime is 1251513631. The next prime is 1251513661. The reversal of 1251513648 is 8463151521.

1251513648 is a `hidden beast` number, since 1 + 2 + 5 + 1 + 5 + 1 + 3 + 648 = 666.

It is a super-2 number, since 2×1251513648² = 3132572822260535808, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 3780843 + ... + 3781173.

Almost surely, 2^1251513648 is an apocalyptic number.

1251513648 is a gapful number since it is divisible by the number (18) 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 1251513648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2277743104).

1251513648 is an abundant number, since it is smaller than the sum of its proper divisors (3303972560).

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

1251513648 is a wasteful number, since it uses less digits than its factorization.

1251513648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405 (or 385 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 1251513648 is about 35376.7387982556. The cubic root of 1251513648 is about 1077.6519770631.

It can be divided in two parts, 1251513 and 648, that added together give a square (1252161 = 1119²).

The spelling of 1251513648 in words is "one billion, two hundred fifty-one million, five hundred thirteen thousand, six hundred forty-eight".