121991442 has 16 divisors (see below), whose sum is σ = 250577472. Its totient is φ = 39564720.

The previous prime is 121991423. The next prime is 121991447. The reversal of 121991442 is 244199121.

It is not an unprimeable number, because it can be changed into a prime (121991447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 274534 + ... + 274977.

It is an arithmetic number, because the mean of its divisors is an integer number (15661092).

Almost surely, 2^121991442 is an apocalyptic number.

121991442 is an abundant number, since it is smaller than the sum of its proper divisors (128586030).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121991442 is a wasteful number, since it uses less digits than its factorization.

121991442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549553.

The product of its digits is 5184, while the sum is 33.

The square root of 121991442 is about 11044.9736079359. The cubic root of 121991442 is about 495.9559691447.

The spelling of 121991442 in words is "one hundred twenty-one million, nine hundred ninety-one thousand, four hundred forty-two".