121566761 has 2 divisors, whose sum is σ = 121566762. Its totient is φ = 121566760.

The previous prime is 121566737. The next prime is 121566787. The reversal of 121566761 is 167665121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 118483225 + 3083536 = 10885^2 + 1756^2 .

It is a cyclic number.

It is not a de Polignac number, because 121566761 - 2¹⁰ = 121565737 is a prime.

It is a super-2 number, since 2×121566761² = 29556954760062242, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (121566061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60783380 + 60783381.

It is an arithmetic number, because the mean of its divisors is an integer number (60783381).

Almost surely, 2^121566761 is an apocalyptic number.

It is an amenable number.

121566761 is a deficient number, since it is larger than the sum of its proper divisors (1).

121566761 is an equidigital number, since it uses as much as digits as its factorization.

121566761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15120, while the sum is 35.

The square root of 121566761 is about 11025.7317670983. The cubic root of 121566761 is about 495.3797867589.

It can be divided in two parts, 1215 and 66761, that added together give a palindrome (67976).

The spelling of 121566761 in words is "one hundred twenty-one million, five hundred sixty-six thousand, seven hundred sixty-one".