121686340 has 72 divisors (see below), whose sum is σ = 279284040. Its totient is φ = 44494848.

The previous prime is 121686329. The next prime is 121686359. The reversal of 121686340 is 43686121.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 1871424 + 119814916 = 1368^2 + 10946^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 213576 + ... + 214144.

It is an arithmetic number, because the mean of its divisors is an integer number (3878945).

Almost surely, 2^121686340 is an apocalyptic number.

121686340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121686340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139642020).

121686340 is an abundant number, since it is smaller than the sum of its proper divisors (157597700).

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

121686340 is a wasteful number, since it uses less digits than its factorization.

121686340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649 (or 630 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 121686340 is about 11031.1531582151. The cubic root of 121686340 is about 495.5421601106.

The spelling of 121686340 in words is "one hundred twenty-one million, six hundred eighty-six thousand, three hundred forty".