1071864821 has 2 divisors, whose sum is σ = 1071864822. Its totient is φ = 1071864820.

The previous prime is 1071864817. The next prime is 1071864839. The reversal of 1071864821 is 1284681701.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1045228900 + 26635921 = 32330^2 + 5161^2 .

It is a cyclic number.

It is not a de Polignac number, because 1071864821 - 2² = 1071864817 is a prime.

It is a super-2 number, since 2×1071864821² = 2297788388994724082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1071864851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 535932410 + 535932411.

It is an arithmetic number, because the mean of its divisors is an integer number (535932411).

Almost surely, 2^1071864821 is an apocalyptic number.

It is an amenable number.

1071864821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1071864821 is an equidigital number, since it uses as much as digits as its factorization.

1071864821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21504, while the sum is 38.

The square root of 1071864821 is about 32739.3466794926. The cubic root of 1071864821 is about 1023.4029687913.

The spelling of 1071864821 in words is "one billion, seventy-one million, eight hundred sixty-four thousand, eight hundred twenty-one".