1156421220 has 24 divisors (see below), whose sum is σ = 3237979584. Its totient is φ = 308378976.

The previous prime is 1156421213. The next prime is 1156421239. The reversal of 1156421220 is 221246511.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9636784 + ... + 9636903.

It is an arithmetic number, because the mean of its divisors is an integer number (134915816).

Almost surely, 2^1156421220 is an apocalyptic number.

1156421220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1156421220 is an abundant number, since it is smaller than the sum of its proper divisors (2081558364).

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

1156421220 is a wasteful number, since it uses less digits than its factorization.

1156421220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19273699 (or 19273697 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 1156421220 is about 34006.1938475919. The cubic root of 1156421220 is about 1049.6359191233.

Adding to 1156421220 its reverse (221246511), we get a palindrome (1377667731).

The spelling of 1156421220 in words is "one billion, one hundred fifty-six million, four hundred twenty-one thousand, two hundred twenty".