825013661 has 4 divisors (see below), whose sum is σ = 836315292. Its totient is φ = 813712032.

The previous prime is 825013619. The next prime is 825013711. The reversal of 825013661 is 166310528.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 279090436 + 545923225 = 16706^2 + 23365^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-825013661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (825013561) 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, 5650706 + ... + 5650851.

It is an arithmetic number, because the mean of its divisors is an integer number (209078823).

Almost surely, 2^825013661 is an apocalyptic number.

It is an amenable number.

825013661 is a deficient number, since it is larger than the sum of its proper divisors (11301631).

825013661 is a wasteful number, since it uses less digits than its factorization.

825013661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11301630.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 825013661 is about 28723.0510391915. The cubic root of 825013661 is about 937.8939044217.

The spelling of 825013661 in words is "eight hundred twenty-five million, thirteen thousand, six hundred sixty-one".