821102401 has 4 divisors (see below), whose sum is σ = 938402752. Its totient is φ = 703802052.

The previous prime is 821102377. The next prime is 821102413. The reversal of 821102401 is 104201128.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 821102401 - 2¹¹ = 821100353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (821102801) 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, 58650165 + ... + 58650178.

It is an arithmetic number, because the mean of its divisors is an integer number (234600688).

Almost surely, 2^821102401 is an apocalyptic number.

It is an amenable number.

821102401 is a deficient number, since it is larger than the sum of its proper divisors (117300351).

821102401 is a wasteful number, since it uses less digits than its factorization.

821102401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117300350.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 821102401 is about 28654.8844178440. The cubic root of 821102401 is about 936.4094202160.

Adding to 821102401 its reverse (104201128), we get a palindrome (925303529).

The spelling of 821102401 in words is "eight hundred twenty-one million, one hundred two thousand, four hundred one".