18523920 has 80 divisors (see below), whose sum is σ = 58210560. Its totient is φ = 4872192.

The previous prime is 18523913. The next prime is 18523933. The reversal of 18523920 is 2932581.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×18523920² = 686271224332800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18472 + ... + 19448.

It is an arithmetic number, because the mean of its divisors is an integer number (727632).

Almost surely, 2^18523920 is an apocalyptic number.

18523920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18523920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29105280).

18523920 is an abundant number, since it is smaller than the sum of its proper divisors (39686640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18523920 is a wasteful number, since it uses less digits than its factorization.

18523920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1072 (or 1066 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 18523920 is about 4303.9423787964. The cubic root of 18523920 is about 264.5925624463.

The spelling of 18523920 in words is "eighteen million, five hundred twenty-three thousand, nine hundred twenty".