1620245775 has 48 divisors (see below), whose sum is σ = 2890020384. Its totient is φ = 797921280.

The previous prime is 1620245771. The next prime is 1620245779. The reversal of 1620245775 is 5775420261.

It is an interprime number because it is at equal distance from previous prime (1620245771) and next prime (1620245779).

It is not a de Polignac number, because 1620245775 - 2² = 1620245771 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620245771) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 55587 + ... + 79563.

It is an arithmetic number, because the mean of its divisors is an integer number (60208758).

Almost surely, 2^1620245775 is an apocalyptic number.

1620245775 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1620245775 is a deficient number, since it is larger than the sum of its proper divisors (1269774609).

1620245775 is a wasteful number, since it uses less digits than its factorization.

1620245775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24060 (or 24055 counting only the distinct ones).

The product of its (nonzero) digits is 117600, while the sum is 39.

The square root of 1620245775 is about 40252.2766436881. The cubic root of 1620245775 is about 1174.5196829643.

The spelling of 1620245775 in words is "one billion, six hundred twenty million, two hundred forty-five thousand, seven hundred seventy-five".