2120642845 has 4 divisors (see below), whose sum is σ = 2544771420. Its totient is φ = 1696514272.

The previous prime is 2120642831. The next prime is 2120642861. The reversal of 2120642845 is 5482460212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1343515716 + 777127129 = 36654^2 + 27877^2 .

It is a cyclic number.

It is not a de Polignac number, because 2120642845 - 2⁵ = 2120642813 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2120642845.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 212064280 + ... + 212064289.

It is an arithmetic number, because the mean of its divisors is an integer number (636192855).

Almost surely, 2^2120642845 is an apocalyptic number.

It is an amenable number.

2120642845 is a deficient number, since it is larger than the sum of its proper divisors (424128575).

2120642845 is an equidigital number, since it uses as much as digits as its factorization.

2120642845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424128574.

The product of its (nonzero) digits is 30720, while the sum is 34.

The square root of 2120642845 is about 46050.4380543769. The cubic root of 2120642845 is about 1284.7614903511.

The spelling of 2120642845 in words is "two billion, one hundred twenty million, six hundred forty-two thousand, eight hundred forty-five".