1247978880 has 128 divisors (see below), whose sum is σ = 4419986400. Its totient is φ = 332789760.

The previous prime is 1247978861. The next prime is 1247978909. The reversal of 1247978880 is 888797421.

It is a happy number.

1247978880 is a `hidden beast` number, since 12 + 479 + 7 + 88 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18831 + ... + 53390.

Almost surely, 2^1247978880 is an apocalyptic number.

1247978880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1247978880 is an abundant number, since it is smaller than the sum of its proper divisors (3172007520).

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

1247978880 is an equidigital number, since it uses as much as digits as its factorization.

1247978880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72249 (or 72231 counting only the distinct ones).

The product of its (nonzero) digits is 1806336, while the sum is 54.

The square root of 1247978880 is about 35326.7445429097. The cubic root of 1247978880 is about 1076.6364490151.

The spelling of 1247978880 in words is "one billion, two hundred forty-seven million, nine hundred seventy-eight thousand, eight hundred eighty".