18815942 has 4 divisors (see below), whose sum is σ = 28223916. Its totient is φ = 9407970.

The previous prime is 18815941. The next prime is 18815987. The reversal of 18815942 is 24951881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24951881 = 1787 ⋅13963.

It is a junction number, because it is equal to n+sod(n) for n = 18815896 and 18815905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18815941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4703984 + ... + 4703987.

It is an arithmetic number, because the mean of its divisors is an integer number (7055979).

Almost surely, 2^18815942 is an apocalyptic number.

18815942 is a deficient number, since it is larger than the sum of its proper divisors (9407974).

18815942 is an equidigital number, since it uses as much as digits as its factorization.

18815942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9407973.

The product of its digits is 23040, while the sum is 38.

The square root of 18815942 is about 4337.7346622402. The cubic root of 18815942 is about 265.9757171569.

The spelling of 18815942 in words is "eighteen million, eight hundred fifteen thousand, nine hundred forty-two".