121521901 has 4 divisors (see below), whose sum is σ = 122006304. Its totient is φ = 121037500.

The previous prime is 121521889. The next prime is 121521941. The reversal of 121521901 is 109125121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 109125121 = 7 ⋅15589303.

It is a cyclic number.

It is not a de Polignac number, because 121521901 - 2⁷ = 121521773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121521941) 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 in 3 ways as a sum of consecutive naturals, for example, 241825 + ... + 242326.

It is an arithmetic number, because the mean of its divisors is an integer number (30501576).

Almost surely, 2^121521901 is an apocalyptic number.

It is an amenable number.

121521901 is a deficient number, since it is larger than the sum of its proper divisors (484403).

121521901 is an equidigital number, since it uses as much as digits as its factorization.

121521901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 484402.

The product of its (nonzero) digits is 180, while the sum is 22.

The square root of 121521901 is about 11023.6972472941. The cubic root of 121521901 is about 495.3188450149.

The spelling of 121521901 in words is "one hundred twenty-one million, five hundred twenty-one thousand, nine hundred one".