31242557 has 2 divisors, whose sum is σ = 31242558. Its totient is φ = 31242556.

The previous prime is 31242551. The next prime is 31242577. The reversal of 31242557 is 75524213.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30846916 + 395641 = 5554^2 + 629^2 .

It is an emirp because it is prime and its reverse (75524213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31242557 - 2¹⁸ = 30980413 is a prime.

It is a super-3 number, since 3×31242557³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31242551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15621278 + 15621279.

It is an arithmetic number, because the mean of its divisors is an integer number (15621279).

Almost surely, 2^31242557 is an apocalyptic number.

It is an amenable number.

31242557 is a deficient number, since it is larger than the sum of its proper divisors (1).

31242557 is an equidigital number, since it uses as much as digits as its factorization.

31242557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8400, while the sum is 29.

The square root of 31242557 is about 5589.5041819467. The cubic root of 31242557 is about 314.9552535751.

The spelling of 31242557 in words is "thirty-one million, two hundred forty-two thousand, five hundred fifty-seven".