18539649 has 24 divisors (see below), whose sum is σ = 28392000. Its totient is φ = 11625120.

The previous prime is 18539621. The next prime is 18539657. The reversal of 18539649 is 94693581.

It is a happy number.

It is not a de Polignac number, because 18539649 - 2⁵ = 18539617 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18539699) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30652 + ... + 31250.

It is an arithmetic number, because the mean of its divisors is an integer number (1183000).

Almost surely, 2^18539649 is an apocalyptic number.

18539649 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

18539649 is a deficient number, since it is larger than the sum of its proper divisors (9852351).

18539649 is a wasteful number, since it uses less digits than its factorization.

18539649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 805 (or 802 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The square root of 18539649 is about 4305.7692692479. The cubic root of 18539649 is about 264.6674313909.

The spelling of 18539649 in words is "eighteen million, five hundred thirty-nine thousand, six hundred forty-nine".