20725649 has 8 divisors (see below), whose sum is σ = 24011520. Its totient is φ = 17521056.

The previous prime is 20725631. The next prime is 20725667. The reversal of 20725649 is 94652702.

It is an interprime number because it is at equal distance from previous prime (20725631) and next prime (20725667).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20725649 - 2¹² = 20721553 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20725619) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19769 + ... + 20790.

It is an arithmetic number, because the mean of its divisors is an integer number (3001440).

Almost surely, 2^20725649 is an apocalyptic number.

It is an amenable number.

20725649 is a deficient number, since it is larger than the sum of its proper divisors (3285871).

20725649 is an equidigital number, since it uses as much as digits as its factorization.

20725649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40639.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 20725649 is about 4552.5431354354. The cubic root of 20725649 is about 274.6856971123.

The spelling of 20725649 in words is "twenty million, seven hundred twenty-five thousand, six hundred forty-nine".