1247663545 has 8 divisors (see below), whose sum is σ = 1498529160. Its totient is φ = 997242240.

The previous prime is 1247663509. The next prime is 1247663581. The reversal of 1247663545 is 5453667421.

It is an interprime number because it is at equal distance from previous prime (1247663509) and next prime (1247663581).

It can be written as a sum of positive squares in 4 ways, for example, as 232349049 + 1015314496 = 15243^2 + 31864^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1247663545 - 2⁹ = 1247663033 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 104866 + ... + 116155.

It is an arithmetic number, because the mean of its divisors is an integer number (187316145).

Almost surely, 2^1247663545 is an apocalyptic number.

It is an amenable number.

1247663545 is a deficient number, since it is larger than the sum of its proper divisors (250865615).

1247663545 is a wasteful number, since it uses less digits than its factorization.

1247663545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222155.

The product of its digits is 604800, while the sum is 43.

The square root of 1247663545 is about 35322.2811409456. The cubic root of 1247663545 is about 1076.5457611147.

The spelling of 1247663545 in words is "one billion, two hundred forty-seven million, six hundred sixty-three thousand, five hundred forty-five".