1264639021009 has 16 divisors (see below), whose sum is σ = 1568734547968. Its totient is φ = 992714812992.

The previous prime is 1264639021007. The next prime is 1264639021021. The reversal of 1264639021009 is 9001209364621.

It is not a de Polignac number, because 1264639021009 - 2¹ = 1264639021007 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1264639021007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54701562 + ... + 54724675.

It is an arithmetic number, because the mean of its divisors is an integer number (98045909248).

Almost surely, 2^{1264639021009} is an apocalyptic number.

It is an amenable number.

1264639021009 is a deficient number, since it is larger than the sum of its proper divisors (304095526959).

1264639021009 is a wasteful number, since it uses less digits than its factorization.

1264639021009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109426384.

The product of its (nonzero) digits is 139968, while the sum is 43.

The spelling of 1264639021009 in words is "one trillion, two hundred sixty-four billion, six hundred thirty-nine million, twenty-one thousand, nine".