820189642 has 8 divisors (see below), whose sum is σ = 1231538976. Its totient is φ = 409676652.

The previous prime is 820189639. The next prime is 820189651. The reversal of 820189642 is 246981028.

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

It is a super-2 number, since 2×820189642² = 1345422097688176328, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 820189595 and 820189604.

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, 206628 + ... + 210559.

It is an arithmetic number, because the mean of its divisors is an integer number (153942372).

Almost surely, 2^820189642 is an apocalyptic number.

820189642 is a deficient number, since it is larger than the sum of its proper divisors (411349334).

820189642 is a wasteful number, since it uses less digits than its factorization.

820189642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418172.

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 820189642 is about 28638.9532280773. The cubic root of 820189642 is about 936.0623124622.

The spelling of 820189642 in words is "eight hundred twenty million, one hundred eighty-nine thousand, six hundred forty-two".