1531023121 has 2 divisors, whose sum is σ = 1531023122. Its totient is φ = 1531023120.

The previous prime is 1531023103. The next prime is 1531023163. The reversal of 1531023121 is 1213201351.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1052288721 + 478734400 = 32439^2 + 21880^2 .

It is an emirp because it is prime and its reverse (1213201351) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1531023121 - 2⁷ = 1531022993 is a prime.

It is not a weakly prime, because it can be changed into another prime (1531023191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 765511560 + 765511561.

It is an arithmetic number, because the mean of its divisors is an integer number (765511561).

Almost surely, 2^1531023121 is an apocalyptic number.

It is an amenable number.

1531023121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1531023121 is an equidigital number, since it uses as much as digits as its factorization.

1531023121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 1531023121 is about 39128.2905453331. The cubic root of 1531023121 is about 1152.5521444246.

Adding to 1531023121 its reverse (1213201351), we get a palindrome (2744224472).

The spelling of 1531023121 in words is "one billion, five hundred thirty-one million, twenty-three thousand, one hundred twenty-one".