312400661 has 4 divisors (see below), whose sum is σ = 312568800. Its totient is φ = 312232524.

The previous prime is 312400637. The next prime is 312400667. The reversal of 312400661 is 166004213.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 166004213 = 7103 ⋅23371.

It is a cyclic number.

It is not a de Polignac number, because 312400661 - 2⁶ = 312400597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312400667) 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, 81251 + ... + 85008.

It is an arithmetic number, because the mean of its divisors is an integer number (78142200).

Almost surely, 2^312400661 is an apocalyptic number.

It is an amenable number.

312400661 is a deficient number, since it is larger than the sum of its proper divisors (168139).

312400661 is a wasteful number, since it uses less digits than its factorization.

312400661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168138.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 312400661 is about 17674.8595751140. The cubic root of 312400661 is about 678.5324905197.

Adding to 312400661 its reverse (166004213), we get a palindrome (478404874).

The spelling of 312400661 in words is "three hundred twelve million, four hundred thousand, six hundred sixty-one".