1661500051 has 2 divisors, whose sum is σ = 1661500052. Its totient is φ = 1661500050.

The previous prime is 1661500033. The next prime is 1661500067. The reversal of 1661500051 is 1500051661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1661500051 - 2⁵ = 1661500019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1661499989 and 1661500025.

It is not a weakly prime, because it can be changed into another prime (1661500751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830750025 + 830750026.

It is an arithmetic number, because the mean of its divisors is an integer number (830750026).

Almost surely, 2^1661500051 is an apocalyptic number.

1661500051 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661500051 is an equidigital number, since it uses as much as digits as its factorization.

1661500051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 1661500051 is about 40761.5020699679. The cubic root of 1661500051 is about 1184.4046933016.

The spelling of 1661500051 in words is "one billion, six hundred sixty-one million, five hundred thousand, fifty-one".