19992897 has 6 divisors (see below), whose sum is σ = 28878642. Its totient is φ = 13328592.

The previous prime is 19992881. The next prime is 19992899. The reversal of 19992897 is 79829991.

It can be written as a sum of positive squares in only one way, i.e., 19000881 + 992016 = 4359^2 + 996^2 .

It is not a de Polignac number, because 19992897 - 2⁴ = 19992881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19992899) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1110708 + ... + 1110725.

It is an arithmetic number, because the mean of its divisors is an integer number (4813107).

Almost surely, 2^19992897 is an apocalyptic number.

It is an amenable number.

19992897 is a deficient number, since it is larger than the sum of its proper divisors (8885745).

19992897 is a wasteful number, since it uses less digits than its factorization.

19992897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2221439 (or 2221436 counting only the distinct ones).

The product of its digits is 734832, while the sum is 54.

The square root of 19992897 is about 4471.3417449352. The cubic root of 19992897 is about 271.4096236740.

It can be divided in two parts, 199 and 92897, that added together give a triangular number (93096 = T₄₃₁).

The spelling of 19992897 in words is "nineteen million, nine hundred ninety-two thousand, eight hundred ninety-seven".