1251121600 has 42 divisors (see below), whose sum is σ = 3078545024. Its totient is φ = 500448000.

The previous prime is 1251121537. The next prime is 1251121603. The reversal of 1251121600 is 61211521.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251121603) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 389376 + ... + 392575.

Almost surely, 2^1251121600 is an apocalyptic number.

1251121600 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1251121600 is an abundant number, since it is smaller than the sum of its proper divisors (1827423424).

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

1251121600 is an equidigital number, since it uses as much as digits as its factorization.

1251121600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 781973 (or 781958 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 19.

The square root of 1251121600 is about 35371.1973221151. The cubic root of 1251121600 is about 1077.5394372260.

The spelling of 1251121600 in words is "one billion, two hundred fifty-one million, one hundred twenty-one thousand, six hundred".