783999221 has 2 divisors, whose sum is σ = 783999222. Its totient is φ = 783999220.

The previous prime is 783999211. The next prime is 783999241. The reversal of 783999221 is 122999387.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 756855121 + 27144100 = 27511^2 + 5210^2 .

It is a cyclic number.

It is not a de Polignac number, because 783999221 - 2⁶ = 783999157 is a prime.

It is a super-2 number, since 2×783999221² = 1229309557057213682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 783999221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (783999211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 391999610 + 391999611.

It is an arithmetic number, because the mean of its divisors is an integer number (391999611).

Almost surely, 2^783999221 is an apocalyptic number.

It is an amenable number.

783999221 is a deficient number, since it is larger than the sum of its proper divisors (1).

783999221 is an equidigital number, since it uses as much as digits as its factorization.

783999221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 50.

The square root of 783999221 is about 27999.9860892823. The cubic root of 783999221 is about 922.0869530094.

The spelling of 783999221 in words is "seven hundred eighty-three million, nine hundred ninety-nine thousand, two hundred twenty-one".