139428891 has 16 divisors (see below), whose sum is σ = 236070400. Its totient is φ = 79673544.

The previous prime is 139428889. The next prime is 139428893. The reversal of 139428891 is 198824931.

139428891 is a `hidden beast` number, since 139 + 428 + 8 + 91 = 666.

It is an interprime number because it is at equal distance from previous prime (139428889) and next prime (139428893).

It is not a de Polignac number, because 139428891 - 2¹ = 139428889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139428893) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 368671 + ... + 369048.

It is an arithmetic number, because the mean of its divisors is an integer number (14754400).

Almost surely, 2^139428891 is an apocalyptic number.

139428891 is a deficient number, since it is larger than the sum of its proper divisors (96641509).

139428891 is an equidigital number, since it uses as much as digits as its factorization.

139428891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 737735 (or 737729 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 139428891 is about 11808.0011432926. The cubic root of 139428891 is about 518.5423812118.

The spelling of 139428891 in words is "one hundred thirty-nine million, four hundred twenty-eight thousand, eight hundred ninety-one".