312687561 has 4 divisors (see below), whose sum is σ = 416916752. Its totient is φ = 208458372.

The previous prime is 312687559. The next prime is 312687581. The reversal of 312687561 is 165786213.

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 not a de Polignac number, because 312687561 - 2¹ = 312687559 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (312687521) 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, 52114591 + ... + 52114596.

It is an arithmetic number, because the mean of its divisors is an integer number (104229188).

Almost surely, 2^312687561 is an apocalyptic number.

It is an amenable number.

312687561 is a deficient number, since it is larger than the sum of its proper divisors (104229191).

312687561 is a wasteful number, since it uses less digits than its factorization.

312687561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104229190.

The product of its digits is 60480, while the sum is 39.

The square root of 312687561 is about 17682.9737600891. The cubic root of 312687561 is about 678.7401420313.

The spelling of 312687561 in words is "three hundred twelve million, six hundred eighty-seven thousand, five hundred sixty-one".