1866613401 has 6 divisors (see below), whose sum is σ = 2696219370. Its totient is φ = 1244408928.

The previous prime is 1866613393. The next prime is 1866613403. The reversal of 1866613401 is 1043166681.

It can be written as a sum of positive squares in only one way, i.e., 1691183376 + 175430025 = 41124^2 + 13245^2 .

It is not a de Polignac number, because 1866613401 - 2³ = 1866613393 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1866613403) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 103700736 + ... + 103700753.

It is an arithmetic number, because the mean of its divisors is an integer number (449369895).

Almost surely, 2^1866613401 is an apocalyptic number.

It is an amenable number.

1866613401 is a deficient number, since it is larger than the sum of its proper divisors (829605969).

1866613401 is a wasteful number, since it uses less digits than its factorization.

1866613401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207401495 (or 207401492 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 1866613401 is about 43204.3215546778. The cubic root of 1866613401 is about 1231.2647886222.

The spelling of 1866613401 in words is "one billion, eight hundred sixty-six million, six hundred thirteen thousand, four hundred one".