1220720843 has 4 divisors (see below), whose sum is σ = 1221309528. Its totient is φ = 1220132160.

The previous prime is 1220720803. The next prime is 1220720881. The reversal of 1220720843 is 3480270221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1220720843 - 2⁶ = 1220720779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1220720803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 291221 + ... + 295382.

It is an arithmetic number, because the mean of its divisors is an integer number (305327382).

Almost surely, 2^1220720843 is an apocalyptic number.

1220720843 is a deficient number, since it is larger than the sum of its proper divisors (588685).

1220720843 is an equidigital number, since it uses as much as digits as its factorization.

1220720843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 588684.

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 1220720843 is about 34938.8157068897. The cubic root of 1220720843 is about 1068.7401373963.

The spelling of 1220720843 in words is "one billion, two hundred twenty million, seven hundred twenty thousand, eight hundred forty-three".