1661668298 has 16 divisors (see below), whose sum is σ = 2710449864. Its totient is φ = 760826880.

The previous prime is 1661668291. The next prime is 1661668301. The reversal of 1661668298 is 8928661661.

It can be written as a sum of positive squares in 4 ways, for example, as 1646168329 + 15499969 = 40573^2 + 3937^2 .

It is a super-2 number, since 2×1661668298² = 5522283065156433608, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1661668291) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 659183 + ... + 661698.

Almost surely, 2^1661668298 is an apocalyptic number.

1661668298 is a deficient number, since it is larger than the sum of its proper divisors (1048781566).

1661668298 is a wasteful number, since it uses less digits than its factorization.

1661668298 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1320937.

The product of its digits is 1492992, while the sum is 53.

The square root of 1661668298 is about 40763.5658155662. The cubic root of 1661668298 is about 1184.4446703915. Note that the first 3 decimals are identical.

The spelling of 1661668298 in words is "one billion, six hundred sixty-one million, six hundred sixty-eight thousand, two hundred ninety-eight".