20749825 has 6 divisors (see below), whose sum is σ = 25729814. Its totient is φ = 16599840.

The previous prime is 20749789. The next prime is 20749831. The reversal of 20749825 is 52894702.

It can be written as a sum of positive squares in 3 ways, for example, as 1468944 + 19280881 = 1212^2 + 4391^2 .

It is not a de Polignac number, because 20749825 - 2⁷ = 20749697 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 414972 + ... + 415021.

Almost surely, 2^20749825 is an apocalyptic number.

20749825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20749825 is a deficient number, since it is larger than the sum of its proper divisors (4979989).

20749825 is an equidigital number, since it uses as much as digits as its factorization.

20749825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 830003 (or 829998 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 20749825 is about 4555.1975807862. The cubic root of 20749825 is about 274.7924604915.

The spelling of 20749825 in words is "twenty million, seven hundred forty-nine thousand, eight hundred twenty-five".