821725642 has 8 divisors (see below), whose sum is σ = 1297461600. Its totient is φ = 389238444.

The previous prime is 821725633. The next prime is 821725673. The reversal of 821725642 is 246527128.

It is a happy number.

821725642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10812142 + ... + 10812217.

It is an arithmetic number, because the mean of its divisors is an integer number (162182700).

Almost surely, 2^821725642 is an apocalyptic number.

821725642 is a deficient number, since it is larger than the sum of its proper divisors (475735958).

821725642 is a wasteful number, since it uses less digits than its factorization.

821725642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21624380.

The product of its digits is 53760, while the sum is 37.

The square root of 821725642 is about 28665.7573072822. The cubic root of 821725642 is about 936.6462811102.

The spelling of 821725642 in words is "eight hundred twenty-one million, seven hundred twenty-five thousand, six hundred forty-two".