121531 has 2 divisors, whose sum is σ = 121532. Its totient is φ = 121530.

The previous prime is 121523. The next prime is 121547. The reversal of 121531 is 135121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 121531 - 2³ = 121523 is a prime.

It is a super-2 number, since 2×121531² = 29539567922, which contains 22 as substring.

It is an Ulam number.

121531 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (121501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60765 + 60766.

It is an arithmetic number, because the mean of its divisors is an integer number (60766).

2¹²¹⁵³¹ is an apocalyptic number.

121531 is a deficient number, since it is larger than the sum of its proper divisors (1).

121531 is an equidigital number, since it uses as much as digits as its factorization.

121531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30, while the sum is 13.

The square root of 121531 is about 348.6129659092. The cubic root of 121531 is about 49.5331207104.

Adding to 121531 its reverse (135121), we get a palindrome (256652).

The spelling of 121531 in words is "one hundred twenty-one thousand, five hundred thirty-one".