7890650921 has 4 divisors (see below), whose sum is σ = 7895746500. Its totient is φ = 7885555344.

The previous prime is 7890650909. The next prime is 7890651029. The reversal of 7890650921 is 1290560987.

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 4234755625 + 3655895296 = 65075^2 + 60464^2 .

It is a cyclic number.

It is not a de Polignac number, because 7890650921 - 2¹⁴ = 7890634537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7890650221) 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, 2545466 + ... + 2548563.

It is an arithmetic number, because the mean of its divisors is an integer number (1973936625).

Almost surely, 2^7890650921 is an apocalyptic number.

It is an amenable number.

7890650921 is a deficient number, since it is larger than the sum of its proper divisors (5095579).

7890650921 is a wasteful number, since it uses less digits than its factorization.

7890650921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5095578.

The product of its (nonzero) digits is 272160, while the sum is 47.

The square root of 7890650921 is about 88829.3359256952. The cubic root of 7890650921 is about 1990.8457404436.

The spelling of 7890650921 in words is "seven billion, eight hundred ninety million, six hundred fifty thousand, nine hundred twenty-one".