121631537 has 4 divisors (see below), whose sum is σ = 121679460. Its totient is φ = 121583616.

The previous prime is 121631527. The next prime is 121631579. The reversal of 121631537 is 735136121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 62710561 + 58920976 = 7919^2 + 7676^2 .

It is a cyclic number.

It is not a de Polignac number, because 121631537 - 2⁶ = 121631473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121631527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19928 + ... + 25305.

It is an arithmetic number, because the mean of its divisors is an integer number (30419865).

Almost surely, 2^121631537 is an apocalyptic number.

It is an amenable number.

121631537 is a deficient number, since it is larger than the sum of its proper divisors (47923).

121631537 is an equidigital number, since it uses as much as digits as its factorization.

121631537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47922.

The product of its digits is 3780, while the sum is 29.

The square root of 121631537 is about 11028.6688680003. The cubic root of 121631537 is about 495.4677576897.

Adding to 121631537 its reverse (735136121), we get a palindrome (856767658).

The spelling of 121631537 in words is "one hundred twenty-one million, six hundred thirty-one thousand, five hundred thirty-seven".