838942991 has 2 divisors, whose sum is σ = 838942992. Its totient is φ = 838942990.

The previous prime is 838942961. The next prime is 838942999. The reversal of 838942991 is 199249838.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-838942991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (838942999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 419471495 + 419471496.

It is an arithmetic number, because the mean of its divisors is an integer number (419471496).

Almost surely, 2^838942991 is an apocalyptic number.

838942991 is a deficient number, since it is larger than the sum of its proper divisors (1).

838942991 is an equidigital number, since it uses as much as digits as its factorization.

838942991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1119744, while the sum is 53.

The square root of 838942991 is about 28964.5126145772. The cubic root of 838942991 is about 943.1428644682.

The spelling of 838942991 in words is "eight hundred thirty-eight million, nine hundred forty-two thousand, nine hundred ninety-one".