1121615820 has 108 divisors (see below), whose sum is σ = 3684176496. Its totient is φ = 276082560.

The previous prime is 1121615819. The next prime is 1121615821. The reversal of 1121615820 is 285161211.

1121615820 is a `hidden beast` number, since 1 + 1 + 21 + 61 + 582 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (1121615819) and next prime (1121615821).

It is not an unprimeable number, because it can be changed into a prime (1121615821) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 11985 + ... + 48855.

Almost surely, 2^1121615820 is an apocalyptic number.

1121615820 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 1121615820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1842088248).

1121615820 is an abundant number, since it is smaller than the sum of its proper divisors (2562560676).

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

1121615820 is a wasteful number, since it uses less digits than its factorization.

1121615820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36912 (or 36894 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 27.

The square root of 1121615820 is about 33490.5332892744. The cubic root of 1121615820 is about 1038.9979932419.

The spelling of 1121615820 in words is "one billion, one hundred twenty-one million, six hundred fifteen thousand, eight hundred twenty".