921993643 has 2 divisors, whose sum is σ = 921993644. Its totient is φ = 921993642.

The previous prime is 921993637. The next prime is 921993701. The reversal of 921993643 is 346399129.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 921993643 - 2⁹ = 921993131 is a prime.

It is a super-2 number, since 2×921993643² = 1700144555464822898, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 921993593 and 921993602.

It is not a weakly prime, because it can be changed into another prime (921993043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 460996821 + 460996822.

It is an arithmetic number, because the mean of its divisors is an integer number (460996822).

Almost surely, 2^921993643 is an apocalyptic number.

921993643 is a deficient number, since it is larger than the sum of its proper divisors (1).

921993643 is an equidigital number, since it uses as much as digits as its factorization.

921993643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 314928, while the sum is 46.

The square root of 921993643 is about 30364.3482228748. The cubic root of 921993643 is about 973.2908537501.

The spelling of 921993643 in words is "nine hundred twenty-one million, nine hundred ninety-three thousand, six hundred forty-three".