18400745 has 16 divisors (see below), whose sum is σ = 24423552. Its totient is φ = 13196160.

The previous prime is 18400741. The next prime is 18400747. The reversal of 18400745 is 54700481.

18400745 = 280² + 281² + ... + 425².

It is not a de Polignac number, because 18400745 - 2² = 18400741 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18400741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1724 + ... + 6306.

It is an arithmetic number, because the mean of its divisors is an integer number (1526472).

Almost surely, 2^18400745 is an apocalyptic number.

It is an amenable number.

18400745 is a deficient number, since it is larger than the sum of its proper divisors (6022807).

18400745 is a wasteful number, since it uses less digits than its factorization.

18400745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4672.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 18400745 is about 4289.6089565367. The cubic root of 18400745 is about 264.0047873711.

The spelling of 18400745 in words is "eighteen million, four hundred thousand, seven hundred forty-five".