139149991 has 2 divisors, whose sum is σ = 139149992. Its totient is φ = 139149990.

The previous prime is 139149971. The next prime is 139150009. The reversal of 139149991 is 199941931.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 139149991 - 2¹⁹ = 138625703 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139149961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69574995 + 69574996.

It is an arithmetic number, because the mean of its divisors is an integer number (69574996).

Almost surely, 2^139149991 is an apocalyptic number.

139149991 is a deficient number, since it is larger than the sum of its proper divisors (1).

139149991 is an equidigital number, since it uses as much as digits as its factorization.

139149991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 78732, while the sum is 46.

The square root of 139149991 is about 11796.1854427607. The cubic root of 139149991 is about 518.1964031645.

The spelling of 139149991 in words is "one hundred thirty-nine million, one hundred forty-nine thousand, nine hundred ninety-one".