19138857 has 4 divisors (see below), whose sum is σ = 25518480. Its totient is φ = 12759236.

The previous prime is 19138849. The next prime is 19138877. The reversal of 19138857 is 75883191.

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 19138857 - 2³ = 19138849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19138807) 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, 3189807 + ... + 3189812.

It is an arithmetic number, because the mean of its divisors is an integer number (6379620).

Almost surely, 2^19138857 is an apocalyptic number.

It is an amenable number.

19138857 is a deficient number, since it is larger than the sum of its proper divisors (6379623).

19138857 is an equidigital number, since it uses as much as digits as its factorization.

19138857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6379622.

The product of its digits is 60480, while the sum is 42.

The square root of 19138857 is about 4374.7979381910. The cubic root of 19138857 is about 267.4886337500.

The spelling of 19138857 in words is "nineteen million, one hundred thirty-eight thousand, eight hundred fifty-seven".