1661491592 has 8 divisors (see below), whose sum is σ = 3115296750. Its totient is φ = 830745792.

The previous prime is 1661491571. The next prime is 1661491621. The reversal of 1661491592 is 2951941661.

It can be written as a sum of positive squares in only one way, i.e., 1578790756 + 82700836 = 39734^2 + 9094^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103843217 + ... + 103843232.

Almost surely, 2^1661491592 is an apocalyptic number.

It is an amenable number.

1661491592 is a deficient number, since it is larger than the sum of its proper divisors (1453805158).

1661491592 is a wasteful number, since it uses less digits than its factorization.

1661491592 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207686455 (or 207686451 counting only the distinct ones).

The product of its digits is 116640, while the sum is 44.

The square root of 1661491592 is about 40761.3983077127. The cubic root of 1661491592 is about 1184.4026832914.

The spelling of 1661491592 in words is "one billion, six hundred sixty-one million, four hundred ninety-one thousand, five hundred ninety-two".