1551660563 has 4 divisors (see below), whose sum is σ = 1551827928. Its totient is φ = 1551493200.

The previous prime is 1551660553. The next prime is 1551660587. The reversal of 1551660563 is 3650661551.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3650661551 = 1709 ⋅2136139.

It is a cyclic number.

It is not a de Polignac number, because 1551660563 - 2²⁴ = 1534883347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1551660503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68906 + ... + 88607.

It is an arithmetic number, because the mean of its divisors is an integer number (387956982).

Almost surely, 2^1551660563 is an apocalyptic number.

1551660563 is a deficient number, since it is larger than the sum of its proper divisors (167365).

1551660563 is an equidigital number, since it uses as much as digits as its factorization.

1551660563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167364.

The product of its (nonzero) digits is 81000, while the sum is 38.

The square root of 1551660563 is about 39391.1228959013. The cubic root of 1551660563 is about 1157.7076615855.

The spelling of 1551660563 in words is "one billion, five hundred fifty-one million, six hundred sixty thousand, five hundred sixty-three".