121890849 has 4 divisors (see below), whose sum is σ = 162521136. Its totient is φ = 81260564.

The previous prime is 121890841. The next prime is 121890851. The reversal of 121890849 is 948098121.

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: 948098121 = 3 ⋅316032707.

It is a cyclic number.

It is not a de Polignac number, because 121890849 - 2³ = 121890841 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121890849.

It is not an unprimeable number, because it can be changed into a prime (121890841) 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, 20315139 + ... + 20315144.

It is an arithmetic number, because the mean of its divisors is an integer number (40630284).

Almost surely, 2^121890849 is an apocalyptic number.

It is an amenable number.

121890849 is a deficient number, since it is larger than the sum of its proper divisors (40630287).

121890849 is an equidigital number, since it uses as much as digits as its factorization.

121890849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40630286.

The product of its (nonzero) digits is 41472, while the sum is 42.

The square root of 121890849 is about 11040.4188779231. The cubic root of 121890849 is about 495.8196114430.

The spelling of 121890849 in words is "one hundred twenty-one million, eight hundred ninety thousand, eight hundred forty-nine".