1217340721515 has 64 divisors (see below), whose sum is σ = 2031234278400. Its totient is φ = 622181683200.

The previous prime is 1217340721483. The next prime is 1217340721543. The reversal of 1217340721515 is 5151270437121.

It is not a de Polignac number, because 1217340721515 - 2⁵ = 1217340721483 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5483475 + ... + 5701155.

It is an arithmetic number, because the mean of its divisors is an integer number (31738035600).

Almost surely, 2^{1217340721515} is an apocalyptic number.

1217340721515 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1217340721515 is a deficient number, since it is larger than the sum of its proper divisors (813893556885).

1217340721515 is a wasteful number, since it uses less digits than its factorization.

1217340721515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217908.

The product of its (nonzero) digits is 58800, while the sum is 39.

The spelling of 1217340721515 in words is "one trillion, two hundred seventeen billion, three hundred forty million, seven hundred twenty-one thousand, five hundred fifteen".