921642643 has 2 divisors, whose sum is σ = 921642644. Its totient is φ = 921642642.

The previous prime is 921642611. The next prime is 921642647. The reversal of 921642643 is 346246129.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 921642643 - 2⁵ = 921642611 is a prime.

It is a super-2 number, since 2×921642643² = 1698850322792050898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (921642647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 460821321 + 460821322.

It is an arithmetic number, because the mean of its divisors is an integer number (460821322).

Almost surely, 2^921642643 is an apocalyptic number.

921642643 is a deficient number, since it is larger than the sum of its proper divisors (1).

921642643 is an equidigital number, since it uses as much as digits as its factorization.

921642643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 37.

The square root of 921642643 is about 30358.5678680665. The cubic root of 921642643 is about 973.1673285128.

The spelling of 921642643 in words is "nine hundred twenty-one million, six hundred forty-two thousand, six hundred forty-three".