18978045 has 16 divisors (see below), whose sum is σ = 31345152. Its totient is φ = 9794880.

The previous prime is 18978041. The next prime is 18978049. The reversal of 18978045 is 54087981.

It is an interprime number because it is at equal distance from previous prime (18978041) and next prime (18978049).

It is not a de Polignac number, because 18978045 - 2² = 18978041 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18977988 and 18978006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18978041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19942 + ... + 20871.

It is an arithmetic number, because the mean of its divisors is an integer number (1959072).

Almost surely, 2^18978045 is an apocalyptic number.

18978045 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18978045 is a deficient number, since it is larger than the sum of its proper divisors (12367107).

18978045 is a wasteful number, since it uses less digits than its factorization.

18978045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40852.

The product of its (nonzero) digits is 80640, while the sum is 42.

The square root of 18978045 is about 4356.3798043789. The cubic root of 18978045 is about 266.7373449808.

The spelling of 18978045 in words is "eighteen million, nine hundred seventy-eight thousand, forty-five".