1249287920 has 20 divisors (see below), whose sum is σ = 2904594600. Its totient is φ = 499715136.

The previous prime is 1249287899. The next prime is 1249287931. The reversal of 1249287920 is 297829421.

It is a tau number, because it is divible by the number of its divisors (20).

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7807970 + ... + 7808129.

It is an arithmetic number, because the mean of its divisors is an integer number (145229730).

Almost surely, 2^1249287920 is an apocalyptic number.

1249287920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1249287920 is an abundant number, since it is smaller than the sum of its proper divisors (1655306680).

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

1249287920 is a wasteful number, since it uses less digits than its factorization.

1249287920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15616112 (or 15616106 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 44.

The square root of 1249287920 is about 35345.2672928074. The cubic root of 1249287920 is about 1077.0127555147.

The spelling of 1249287920 in words is "one billion, two hundred forty-nine million, two hundred eighty-seven thousand, nine hundred twenty".