19855057 has 4 divisors (see below), whose sum is σ = 20900080. Its totient is φ = 18810036.

The previous prime is 19855021. The next prime is 19855061. The reversal of 19855057 is 75055891.

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, and also an emirpimes, since its reverse is a distinct semiprime: 75055891 = 157 ⋅478063.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19855057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19855007) 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, 522483 + ... + 522520.

It is an arithmetic number, because the mean of its divisors is an integer number (5225020).

Almost surely, 2^19855057 is an apocalyptic number.

It is an amenable number.

19855057 is a deficient number, since it is larger than the sum of its proper divisors (1045023).

19855057 is a wasteful number, since it uses less digits than its factorization.

19855057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1045022.

The product of its (nonzero) digits is 63000, while the sum is 40.

The square root of 19855057 is about 4455.9013678492. The cubic root of 19855057 is about 270.7844448140.

It can be divided in two parts, 198 and 55057, that added together give a palindrome (55255).

The spelling of 19855057 in words is "nineteen million, eight hundred fifty-five thousand, fifty-seven".