121505899 has 2 divisors, whose sum is σ = 121505900. Its totient is φ = 121505898.

The previous prime is 121505887. The next prime is 121505903. The reversal of 121505899 is 998505121.

It is a strong prime.

It is an emirp because it is prime and its reverse (998505121) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121505899 is a prime.

It is not a weakly prime, because it can be changed into another prime (121505809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60752949 + 60752950.

It is an arithmetic number, because the mean of its divisors is an integer number (60752950).

Almost surely, 2^121505899 is an apocalyptic number.

121505899 is a deficient number, since it is larger than the sum of its proper divisors (1).

121505899 is an equidigital number, since it uses as much as digits as its factorization.

121505899 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 40.

The square root of 121505899 is about 11022.9714233504. The cubic root of 121505899 is about 495.2971028707.

The spelling of 121505899 in words is "one hundred twenty-one million, five hundred five thousand, eight hundred ninety-nine".