1220957845 has 4 divisors (see below), whose sum is σ = 1465149420. Its totient is φ = 976766272.

The previous prime is 1220957813. The next prime is 1220957849. The reversal of 1220957845 is 5487590221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5487590221 = 29 ⋅189227249.

It can be written as a sum of positive squares in 2 ways, for example, as 264973284 + 955984561 = 16278^2 + 30919^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220957845 - 2⁵ = 1220957813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220957849) 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, 122095780 + ... + 122095789.

It is an arithmetic number, because the mean of its divisors is an integer number (366287355).

Almost surely, 2^1220957845 is an apocalyptic number.

It is an amenable number.

1220957845 is a deficient number, since it is larger than the sum of its proper divisors (244191575).

1220957845 is an equidigital number, since it uses as much as digits as its factorization.

1220957845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244191574.

The product of its (nonzero) digits is 201600, while the sum is 43.

The square root of 1220957845 is about 34942.2072141987. The cubic root of 1220957845 is about 1068.8092979422.

The spelling of 1220957845 in words is "one billion, two hundred twenty million, nine hundred fifty-seven thousand, eight hundred forty-five".