821711601 has 16 divisors (see below), whose sum is σ = 1281422400. Its totient is φ = 518975424.

The previous prime is 821711599. The next prime is 821711617. The reversal of 821711601 is 106117128.

It is not a de Polignac number, because 821711601 - 2¹ = 821711599 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (821711641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 800376 + ... + 801401.

It is an arithmetic number, because the mean of its divisors is an integer number (80088900).

Almost surely, 2^821711601 is an apocalyptic number.

It is an amenable number.

821711601 is a deficient number, since it is larger than the sum of its proper divisors (459710799).

821711601 is a wasteful number, since it uses less digits than its factorization.

821711601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1601805 (or 1601799 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 27.

The square root of 821711601 is about 28665.5123973042. The cubic root of 821711601 is about 936.6409461888.

Adding to 821711601 its reverse (106117128), we get a palindrome (927828729).

The spelling of 821711601 in words is "eight hundred twenty-one million, seven hundred eleven thousand, six hundred one".