1247213664 has 36 divisors (see below), whose sum is σ = 3546764676. Its totient is φ = 415737792.

The previous prime is 1247213651. The next prime is 1247213699. The reversal of 1247213664 is 4663127421.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2165014 + ... + 2165589.

It is an arithmetic number, because the mean of its divisors is an integer number (98521241).

Almost surely, 2^1247213664 is an apocalyptic number.

It is an amenable number.

1247213664 is an abundant number, since it is smaller than the sum of its proper divisors (2299551012).

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

1247213664 is a wasteful number, since it uses less digits than its factorization.

1247213664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4330619 (or 4330608 counting only the distinct ones).

The product of its digits is 48384, while the sum is 36.

The square root of 1247213664 is about 35315.9123342439. The cubic root of 1247213664 is about 1076.4163523734.

The spelling of 1247213664 in words is "one billion, two hundred forty-seven million, two hundred thirteen thousand, six hundred sixty-four".