19945157 has 4 divisors (see below), whose sum is σ = 19980780. Its totient is φ = 19909536.

The previous prime is 19945153. The next prime is 19945171. The reversal of 19945157 is 75154991.

It is a Cunningham number, because it is equal to 4466²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3290596 + 16654561 = 1814^2 + 4081^2 .

It is a cyclic number.

It is not a de Polignac number, because 19945157 - 2² = 19945153 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19945151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16958 + ... + 18095.

It is an arithmetic number, because the mean of its divisors is an integer number (4995195).

Almost surely, 2^19945157 is an apocalyptic number.

It is an amenable number.

19945157 is a deficient number, since it is larger than the sum of its proper divisors (35623).

19945157 is an equidigital number, since it uses as much as digits as its factorization.

19945157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35622.

The product of its digits is 56700, while the sum is 41.

The square root of 19945157 is about 4466.0001119570. Note that the first 3 decimals coincide. The cubic root of 19945157 is about 271.1934231850.

It can be divided in two parts, 19945 and 157, that added together give a palindrome (20102).

The spelling of 19945157 in words is "nineteen million, nine hundred forty-five thousand, one hundred fifty-seven".