1251251380 has 12 divisors (see below), whose sum is σ = 2627627940. Its totient is φ = 500500544.

The previous prime is 1251251369. The next prime is 1251251387. The reversal of 1251251380 is 831521521.

It can be written as a sum of positive squares in 2 ways, for example, as 156700324 + 1094551056 = 12518^2 + 33084^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251251387) 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 3 ways as a sum of consecutive naturals, for example, 31281265 + ... + 31281304.

It is an arithmetic number, because the mean of its divisors is an integer number (218968995).

Almost surely, 2^1251251380 is an apocalyptic number.

1251251380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1251251380 is an abundant number, since it is smaller than the sum of its proper divisors (1376376560).

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

1251251380 is a wasteful number, since it uses less digits than its factorization.

1251251380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62562578 (or 62562576 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 28.

The square root of 1251251380 is about 35373.0318180390. The cubic root of 1251251380 is about 1077.5766939917.

The spelling of 1251251380 in words is "one billion, two hundred fifty-one million, two hundred fifty-one thousand, three hundred eighty".