18521725 has 12 divisors (see below), whose sum is σ = 23708800. Its totient is φ = 14338800.

The previous prime is 18521689. The next prime is 18521729. The reversal of 18521725 is 52712581.

It is not a de Polignac number, because 18521725 - 2⁹ = 18521213 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18521729) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11175 + ... + 12724.

Almost surely, 2^18521725 is an apocalyptic number.

It is an amenable number.

18521725 is a deficient number, since it is larger than the sum of its proper divisors (5187075).

18521725 is a wasteful number, since it uses less digits than its factorization.

18521725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23940 (or 23935 counting only the distinct ones).

The product of its digits is 5600, while the sum is 31.

The square root of 18521725 is about 4303.6873724749. The cubic root of 18521725 is about 264.5821110297.

The spelling of 18521725 in words is "eighteen million, five hundred twenty-one thousand, seven hundred twenty-five".