25728739 has 4 divisors (see below), whose sum is σ = 25899280. Its totient is φ = 25558200.

The previous prime is 25728721. The next prime is 25728809. The reversal of 25728739 is 93782752.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 25728739 - 2¹¹ = 25726691 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 25728695 and 25728704.

It is not an unprimeable number, because it can be changed into a prime (25728709) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85044 + ... + 85345.

It is an arithmetic number, because the mean of its divisors is an integer number (6474820).

Almost surely, 2^25728739 is an apocalyptic number.

25728739 is a deficient number, since it is larger than the sum of its proper divisors (170541).

25728739 is a wasteful number, since it uses less digits than its factorization.

25728739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170540.

The product of its digits is 211680, while the sum is 43.

The square root of 25728739 is about 5072.3504413635. The cubic root of 25728739 is about 295.2157341797.

It can be divided in two parts, 2572 and 8739, that added together give a palindrome (11311).

The spelling of 25728739 in words is "twenty-five million, seven hundred twenty-eight thousand, seven hundred thirty-nine".