821695541 has 6 divisors (see below), whose sum is σ = 850189590. Its totient is φ = 793212168.

The previous prime is 821695531. The next prime is 821695543. The reversal of 821695541 is 145596128.

It can be written as a sum of positive squares in only one way, i.e., 708358225 + 113337316 = 26615^2 + 10646^2 .

It is a de Polignac number, because none of the positive numbers 2^k-821695541 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 (821695543) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 151706 + ... + 157028.

It is an arithmetic number, because the mean of its divisors is an integer number (141698265).

Almost surely, 2^821695541 is an apocalyptic number.

It is an amenable number.

821695541 is a deficient number, since it is larger than the sum of its proper divisors (28494049).

821695541 is an frugal number, since it uses more digits than its factorization.

821695541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10675 (or 5352 counting only the distinct ones).

The product of its digits is 86400, while the sum is 41.

The square root of 821695541 is about 28665.2322683770. The cubic root of 821695541 is about 936.6348440675.

The spelling of 821695541 in words is "eight hundred twenty-one million, six hundred ninety-five thousand, five hundred forty-one".