1646997591503 has 24 divisors (see below), whose sum is σ = 1867245058224. Its totient is φ = 1450550471040.

The previous prime is 1646997591487. The next prime is 1646997591529. The reversal of 1646997591503 is 3051957996461.

It is not a de Polignac number, because 1646997591503 - 2⁴ = 1646997591487 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1646997591503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1646997591103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 253700 + ... + 1832582.

It is an arithmetic number, because the mean of its divisors is an integer number (77801877426).

Almost surely, 2^{1646997591503} is an apocalyptic number.

1646997591503 is a deficient number, since it is larger than the sum of its proper divisors (220247466721).

1646997591503 is a wasteful number, since it uses less digits than its factorization.

1646997591503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1579175 (or 1579164 counting only the distinct ones).

The product of its (nonzero) digits is 55112400, while the sum is 65.

The spelling of 1646997591503 in words is "one trillion, six hundred forty-six billion, nine hundred ninety-seven million, five hundred ninety-one thousand, five hundred three".