121620780 has 144 divisors (see below), whose sum is σ = 398623680. Its totient is φ = 29922816.

The previous prime is 121620773. The next prime is 121620787. The reversal of 121620780 is 87026121.

It is an interprime number because it is at equal distance from previous prime (121620773) and next prime (121620787).

It is a super-2 number, since 2×121620780² = 29583228255616800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (121620787) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 119554 + ... + 120566.

It is an arithmetic number, because the mean of its divisors is an integer number (2768220).

Almost surely, 2^121620780 is an apocalyptic number.

121620780 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 121620780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (199311840).

121620780 is an abundant number, since it is smaller than the sum of its proper divisors (277002900).

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

121620780 is a wasteful number, since it uses less digits than its factorization.

121620780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1080 (or 1075 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 121620780 is about 11028.1811737022. The cubic root of 121620780 is about 495.4531509960.

The spelling of 121620780 in words is "one hundred twenty-one million, six hundred twenty thousand, seven hundred eighty".