1247993864 has 16 divisors (see below), whose sum is σ = 2519987820. Its totient is φ = 575997120.

The previous prime is 1247993863. The next prime is 1247993897. The reversal of 1247993864 is 4683997421.

It can be written as a sum of positive squares in 2 ways, for example, as 1132860964 + 115132900 = 33658^2 + 10730^2 .

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1247993863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5999867 + ... + 6000074.

Almost surely, 2^1247993864 is an apocalyptic number.

It is an amenable number.

1247993864 is an abundant number, since it is smaller than the sum of its proper divisors (1271993956).

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

1247993864 is a wasteful number, since it uses less digits than its factorization.

1247993864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11999960 (or 11999956 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 53.

The square root of 1247993864 is about 35326.9566195561. The cubic root of 1247993864 is about 1076.6407579171.

The spelling of 1247993864 in words is "one billion, two hundred forty-seven million, nine hundred ninety-three thousand, eight hundred sixty-four".