18400534 has 4 divisors (see below), whose sum is σ = 27600804. Its totient is φ = 9200266.

The previous prime is 18400523. The next prime is 18400541. The reversal of 18400534 is 43500481.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 18400499 and 18400508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4600132 + ... + 4600135.

It is an arithmetic number, because the mean of its divisors is an integer number (6900201).

Almost surely, 2^18400534 is an apocalyptic number.

18400534 is a deficient number, since it is larger than the sum of its proper divisors (9200270).

18400534 is an equidigital number, since it uses as much as digits as its factorization.

18400534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9200269.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 18400534 is about 4289.5843621498. The cubic root of 18400534 is about 264.0037782594.

The spelling of 18400534 in words is "eighteen million, four hundred thousand, five hundred thirty-four".