121681890 has 96 divisors (see below), whose sum is σ = 363355200. Its totient is φ = 27941760.

The previous prime is 121681877. The next prime is 121681907. The reversal of 121681890 is 98186121.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15576 + ... + 22044.

It is an arithmetic number, because the mean of its divisors is an integer number (3784950).

Almost surely, 2^121681890 is an apocalyptic number.

121681890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 121681890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (181677600).

121681890 is an abundant number, since it is smaller than the sum of its proper divisors (241673310).

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

121681890 is a wasteful number, since it uses less digits than its factorization.

121681890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6512 (or 6509 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 36.

The square root of 121681890 is about 11030.9514548837. The cubic root of 121681890 is about 495.5361194723.

The spelling of 121681890 in words is "one hundred twenty-one million, six hundred eighty-one thousand, eight hundred ninety".