19139657 has 4 divisors (see below), whose sum is σ = 19971840. Its totient is φ = 18307476.

The previous prime is 19139647. The next prime is 19139663. The reversal of 19139657 is 75693191.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19139657 - 2²⁰ = 18091081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19139647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 416057 + ... + 416102.

It is an arithmetic number, because the mean of its divisors is an integer number (4992960).

Almost surely, 2^19139657 is an apocalyptic number.

It is an amenable number.

19139657 is a deficient number, since it is larger than the sum of its proper divisors (832183).

19139657 is an equidigital number, since it uses as much as digits as its factorization.

19139657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 832182.

The product of its digits is 51030, while the sum is 41.

The square root of 19139657 is about 4374.8893700298. The cubic root of 19139657 is about 267.4923606867.

The spelling of 19139657 in words is "nineteen million, one hundred thirty-nine thousand, six hundred fifty-seven".