121643540 has 12 divisors (see below), whose sum is σ = 255451476. Its totient is φ = 48657408.

The previous prime is 121643539. The next prime is 121643569. The reversal of 121643540 is 45346121.

It can be written as a sum of positive squares in 2 ways, for example, as 63457156 + 58186384 = 7966^2 + 7628^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3041069 + ... + 3041108.

It is an arithmetic number, because the mean of its divisors is an integer number (21287623).

Almost surely, 2^121643540 is an apocalyptic number.

121643540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121643540 is an abundant number, since it is smaller than the sum of its proper divisors (133807936).

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

121643540 is a wasteful number, since it uses less digits than its factorization.

121643540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6082186 (or 6082184 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 121643540 is about 11029.2130272291. The cubic root of 121643540 is about 495.4840552827.

Adding to 121643540 its reverse (45346121), we get a palindrome (166989661).

The spelling of 121643540 in words is "one hundred twenty-one million, six hundred forty-three thousand, five hundred forty".