1042138991 has 2 divisors, whose sum is σ = 1042138992. Its totient is φ = 1042138990.

The previous prime is 1042138973. The next prime is 1042139009. The reversal of 1042138991 is 1998312401.

It is a balanced prime because it is at equal distance from previous prime (1042138973) and next prime (1042139009).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1042138991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1042138931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 521069495 + 521069496.

It is an arithmetic number, because the mean of its divisors is an integer number (521069496).

Almost surely, 2^1042138991 is an apocalyptic number.

1042138991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1042138991 is an equidigital number, since it uses as much as digits as its factorization.

1042138991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 1042138991 is about 32282.1776062272. The cubic root of 1042138991 is about 1013.8535239508.

The spelling of 1042138991 in words is "one billion, forty-two million, one hundred thirty-eight thousand, nine hundred ninety-one".