121620731 has 2 divisors, whose sum is σ = 121620732. Its totient is φ = 121620730.

The previous prime is 121620713. The next prime is 121620749. The reversal of 121620731 is 137026121.

Together with previous prime (121620713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a balanced prime because it is at equal distance from previous prime (121620713) and next prime (121620749).

It is an emirp because it is prime and its reverse (137026121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121620731 - 2²² = 117426427 is a prime.

It is a super-2 number, since 2×121620731² = 29583204417948722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 121620697 and 121620706.

It is not a weakly prime, because it can be changed into another prime (121620131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60810365 + 60810366.

It is an arithmetic number, because the mean of its divisors is an integer number (60810366).

Almost surely, 2^121620731 is an apocalyptic number.

121620731 is a deficient number, since it is larger than the sum of its proper divisors (1).

121620731 is an equidigital number, since it uses as much as digits as its factorization.

121620731 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 121620731 is about 11028.1789521208. The cubic root of 121620731 is about 495.4530844580.

Adding to 121620731 its reverse (137026121), we get a palindrome (258646852).

The spelling of 121620731 in words is "one hundred twenty-one million, six hundred twenty thousand, seven hundred thirty-one".