1866428131 has 4 divisors (see below), whose sum is σ = 1880051832. Its totient is φ = 1852804432.

The previous prime is 1866428099. The next prime is 1866428143. The reversal of 1866428131 is 1318246681.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1866428131 - 2⁵ = 1866428099 is a prime.

It is a super-2 number, since 2×1866428131² = 6967107936376306322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1866428171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6811645 + ... + 6811918.

It is an arithmetic number, because the mean of its divisors is an integer number (470012958).

Almost surely, 2^1866428131 is an apocalyptic number.

1866428131 is a deficient number, since it is larger than the sum of its proper divisors (13623701).

1866428131 is a wasteful number, since it uses less digits than its factorization.

1866428131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13623700.

The product of its digits is 55296, while the sum is 40.

The square root of 1866428131 is about 43202.1773872568. The cubic root of 1866428131 is about 1231.2240510357.

The spelling of 1866428131 in words is "one billion, eight hundred sixty-six million, four hundred twenty-eight thousand, one hundred thirty-one".