25764642 has 40 divisors (see below), whose sum is σ = 58156956. Its totient is φ = 8525088.

The previous prime is 25764581. The next prime is 25764643. The reversal of 25764642 is 24646752.

25764642 is a `hidden beast` number, since 2 + 5 + 7 + 6 + 4 + 642 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20331081 + 5433561 = 4509^2 + 2331^2 .

It is a junction number, because it is equal to n+sod(n) for n = 25764597 and 25764606.

It is not an unprimeable number, because it can be changed into a prime (25764643) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 24928 + ... + 25940.

Almost surely, 2^25764642 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25764642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29078478).

25764642 is an abundant number, since it is smaller than the sum of its proper divisors (32392314).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25764642 is a wasteful number, since it uses less digits than its factorization.

25764642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1184 (or 1175 counting only the distinct ones).

The product of its digits is 80640, while the sum is 36.

The square root of 25764642 is about 5075.8882966433. Note that the first 3 decimals coincide. The cubic root of 25764642 is about 295.3529893086.

The spelling of 25764642 in words is "twenty-five million, seven hundred sixty-four thousand, six hundred forty-two".