18919953 has 32 divisors (see below), whose sum is σ = 31785600. Its totient is φ = 11026368.

The previous prime is 18919949. The next prime is 18919969. The reversal of 18919953 is 35991981.

It is not a de Polignac number, because 18919953 - 2² = 18919949 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18919899 and 18919908.

It is not an unprimeable number, because it can be changed into a prime (18919973) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5251 + ... + 8087.

It is an arithmetic number, because the mean of its divisors is an integer number (993300).

Almost surely, 2^18919953 is an apocalyptic number.

18919953 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18919953 is a deficient number, since it is larger than the sum of its proper divisors (12865647).

18919953 is a wasteful number, since it uses less digits than its factorization.

18919953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2878 (or 2872 counting only the distinct ones).

The product of its digits is 87480, while the sum is 45.

The square root of 18919953 is about 4349.7072315272. The cubic root of 18919953 is about 266.4649048494.

The spelling of 18919953 in words is "eighteen million, nine hundred nineteen thousand, nine hundred fifty-three".