312121551 has 16 divisors (see below), whose sum is σ = 476900864. Its totient is φ = 177872544.

The previous prime is 312121543. The next prime is 312121553. The reversal of 312121551 is 155121213.

It is not a de Polignac number, because 312121551 - 2³ = 312121543 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312121553) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12091 + ... + 27756.

It is an arithmetic number, because the mean of its divisors is an integer number (29806304).

Almost surely, 2^312121551 is an apocalyptic number.

312121551 is a deficient number, since it is larger than the sum of its proper divisors (164779313).

312121551 is a wasteful number, since it uses less digits than its factorization.

312121551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40230.

The product of its digits is 300, while the sum is 21.

The square root of 312121551 is about 17666.9621327494. The cubic root of 312121551 is about 678.3303551891.

Adding to 312121551 its reverse (155121213), we get a palindrome (467242764).

The spelling of 312121551 in words is "three hundred twelve million, one hundred twenty-one thousand, five hundred fifty-one".