121991730 has 32 divisors (see below), whose sum is σ = 334606464. Its totient is φ = 27883776.

The previous prime is 121991729. The next prime is 121991767. The reversal of 121991730 is 37199121.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 121991691 and 121991700.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 290247 + ... + 290666.

It is an arithmetic number, because the mean of its divisors is an integer number (10456452).

Almost surely, 2^121991730 is an apocalyptic number.

121991730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

121991730 is an abundant number, since it is smaller than the sum of its proper divisors (212614734).

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

121991730 is a wasteful number, since it uses less digits than its factorization.

121991730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 580930.

The product of its (nonzero) digits is 3402, while the sum is 33.

The square root of 121991730 is about 11044.9866455329. The cubic root of 121991730 is about 495.9563594322.

The spelling of 121991730 in words is "one hundred twenty-one million, nine hundred ninety-one thousand, seven hundred thirty".