121271220 has 144 divisors (see below), whose sum is σ = 424744320. Its totient is φ = 27433728.

The previous prime is 121271219. The next prime is 121271257. The reversal of 121271220 is 22172121.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 121271193 and 121271202.

It is a congruent 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, 136899 + ... + 137781.

Almost surely, 2^121271220 is an apocalyptic number.

121271220 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 121271220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (212372160).

121271220 is an abundant number, since it is smaller than the sum of its proper divisors (303473100).

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

121271220 is a wasteful number, since it uses less digits than its factorization.

121271220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1014 (or 1009 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 121271220 is about 11012.3212811832. The cubic root of 121271220 is about 494.9780216749.

Subtracting from 121271220 its reverse (22172121), we obtain a palindrome (99099099).

The spelling of 121271220 in words is "one hundred twenty-one million, two hundred seventy-one thousand, two hundred twenty".