1866880401 has 4 divisors (see below), whose sum is σ = 2489173872. Its totient is φ = 1244586932.

The previous prime is 1866880391. The next prime is 1866880447. The reversal of 1866880401 is 1040886681.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1866880401 - 2⁵ = 1866880369 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1866880501) 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, 311146731 + ... + 311146736.

It is an arithmetic number, because the mean of its divisors is an integer number (622293468).

Almost surely, 2^1866880401 is an apocalyptic number.

It is an amenable number.

1866880401 is a deficient number, since it is larger than the sum of its proper divisors (622293471).

1866880401 is an equidigital number, since it uses as much as digits as its factorization.

1866880401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622293470.

The product of its (nonzero) digits is 73728, while the sum is 42.

The square root of 1866880401 is about 43207.4114128583. The cubic root of 1866880401 is about 1231.3234924447.

The spelling of 1866880401 in words is "one billion, eight hundred sixty-six million, eight hundred eighty thousand, four hundred one".