121204640 has 48 divisors (see below), whose sum is σ = 291769128. Its totient is φ = 47563776.

The previous prime is 121204631. The next prime is 121204649. The reversal of 121204640 is 46402121.

It is an interprime number because it is at equal distance from previous prime (121204631) and next prime (121204649).

It can be written as a sum of positive squares in 4 ways, for example, as 69422224 + 51782416 = 8332^2 + 7196^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (121204649) 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, 1334 + ... + 15626.

Almost surely, 2^121204640 is an apocalyptic number.

121204640 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 121204640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145884564).

121204640 is an abundant number, since it is smaller than the sum of its proper divisors (170564488).

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

121204640 is a wasteful number, since it uses less digits than its factorization.

121204640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14361 (or 14353 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 121204640 is about 11009.2978886031. The cubic root of 121204640 is about 494.8874212571.

Adding to 121204640 its reverse (46402121), we get a palindrome (167606761).

The spelling of 121204640 in words is "one hundred twenty-one million, two hundred four thousand, six hundred forty".