231015121 has 2 divisors, whose sum is σ = 231015122. Its totient is φ = 231015120.

The previous prime is 231015119. The next prime is 231015157. The reversal of 231015121 is 121510132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 162307600 + 68707521 = 12740^2 + 8289^2 .

It is a cyclic number.

It is not a de Polignac number, because 231015121 - 2¹ = 231015119 is a prime.

It is a super-2 number, since 2×231015121² = 106735972261289282, which contains 22 as substring.

Together with 231015119, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 231015095 and 231015104.

It is not a weakly prime, because it can be changed into another prime (231015101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115507560 + 115507561.

It is an arithmetic number, because the mean of its divisors is an integer number (115507561).

Almost surely, 2^231015121 is an apocalyptic number.

It is an amenable number.

231015121 is a deficient number, since it is larger than the sum of its proper divisors (1).

231015121 is an equidigital number, since it uses as much as digits as its factorization.

231015121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 231015121 is about 15199.1815898094. The cubic root of 231015121 is about 613.5926317430.

Adding to 231015121 its reverse (121510132), we get a palindrome (352525253).

The spelling of 231015121 in words is "two hundred thirty-one million, fifteen thousand, one hundred twenty-one".