1661550164 has 6 divisors (see below), whose sum is σ = 2907712794. Its totient is φ = 830775080.

The previous prime is 1661550161. The next prime is 1661550169. The reversal of 1661550164 is 4610551661.

It can be written as a sum of positive squares in only one way, i.e., 1039546564 + 622003600 = 32242^2 + 24940^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661550161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 207693767 + ... + 207693774.

It is an arithmetic number, because the mean of its divisors is an integer number (484618799).

Almost surely, 2^1661550164 is an apocalyptic number.

It is an amenable number.

1661550164 is a deficient number, since it is larger than the sum of its proper divisors (1246162630).

1661550164 is a wasteful number, since it uses less digits than its factorization.

1661550164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415387545 (or 415387543 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 35.

The square root of 1661550164 is about 40762.1167752608. The cubic root of 1661550164 is about 1184.4166009099.

The spelling of 1661550164 in words is "one billion, six hundred sixty-one million, five hundred fifty thousand, one hundred sixty-four".