1247994866 has 4 divisors (see below), whose sum is σ = 1871992302. Its totient is φ = 623997432.

The previous prime is 1247994823. The next prime is 1247994883. The reversal of 1247994866 is 6684997421.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1236577225 + 11417641 = 35165^2 + 3379^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 311998715 + ... + 311998718.

Almost surely, 2^1247994866 is an apocalyptic number.

1247994866 is a deficient number, since it is larger than the sum of its proper divisors (623997436).

1247994866 is an equidigital number, since it uses as much as digits as its factorization.

1247994866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 623997435.

The product of its digits is 5225472, while the sum is 56.

The square root of 1247994866 is about 35326.9708013580. The cubic root of 1247994866 is about 1076.6410460579.

The spelling of 1247994866 in words is "one billion, two hundred forty-seven million, nine hundred ninety-four thousand, eight hundred sixty-six".