19121825 has 12 divisors (see below), whose sum is σ = 23948988. Its totient is φ = 15144000.

The previous prime is 19121803. The next prime is 19121827. The reversal of 19121825 is 52812191.

It can be written as a sum of positive squares in 6 ways, for example, as 4734976 + 14386849 = 2176^2 + 3793^2 .

It is not a de Polignac number, because 19121825 - 2⁸ = 19121569 is a prime.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19121827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1262 + ... + 6311.

It is an arithmetic number, because the mean of its divisors is an integer number (1995749).

Almost surely, 2^19121825 is an apocalyptic number.

19121825 is the 2525-th octagonal number.

It is an amenable number.

19121825 is a deficient number, since it is larger than the sum of its proper divisors (4827163).

19121825 is a wasteful number, since it uses less digits than its factorization.

19121825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7684 (or 7679 counting only the distinct ones).

The product of its digits is 1440, while the sum is 29.

The square root of 19121825 is about 4372.8509007283. The cubic root of 19121825 is about 267.4092626130.

The spelling of 19121825 in words is "nineteen million, one hundred twenty-one thousand, eight hundred twenty-five".