1990245773 has 4 divisors (see below), whose sum is σ = 2001241788. Its totient is φ = 1979249760.

The previous prime is 1990245769. The next prime is 1990245809. The reversal of 1990245773 is 3775420991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3775420991 = 463 ⋅8154257.

It can be written as a sum of positive squares in 2 ways, for example, as 47375689 + 1942870084 = 6883^2 + 44078^2 .

It is a cyclic number.

It is not a de Polignac number, because 1990245773 - 2² = 1990245769 is a prime.

It is a super-2 number, since 2×1990245773² = 7922156473888735058, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990245073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5497736 + ... + 5498097.

It is an arithmetic number, because the mean of its divisors is an integer number (500310447).

Almost surely, 2^1990245773 is an apocalyptic number.

It is an amenable number.

1990245773 is a deficient number, since it is larger than the sum of its proper divisors (10996015).

1990245773 is a wasteful number, since it uses less digits than its factorization.

1990245773 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10996014.

The product of its (nonzero) digits is 476280, while the sum is 47.

The square root of 1990245773 is about 44612.1706824494. The cubic root of 1990245773 is about 1257.8694516583.

The spelling of 1990245773 in words is "one billion, nine hundred ninety million, two hundred forty-five thousand, seven hundred seventy-three".