913637821 has 2 divisors, whose sum is σ = 913637822. Its totient is φ = 913637820.

The previous prime is 913637761. The next prime is 913637861. The reversal of 913637821 is 128736319.

It is an a-pointer prime, because the next prime (913637861) can be obtained adding 913637821 to its sum of digits (40).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 841812196 + 71825625 = 29014^2 + 8475^2 .

It is a cyclic number.

It is not a de Polignac number, because 913637821 - 2⁷ = 913637693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (913637861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 456818910 + 456818911.

It is an arithmetic number, because the mean of its divisors is an integer number (456818911).

Almost surely, 2^913637821 is an apocalyptic number.

It is an amenable number.

913637821 is a deficient number, since it is larger than the sum of its proper divisors (1).

913637821 is an equidigital number, since it uses as much as digits as its factorization.

913637821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 40.

The square root of 913637821 is about 30226.4424138866. The cubic root of 913637821 is about 970.3416874683.

The spelling of 913637821 in words is "nine hundred thirteen million, six hundred thirty-seven thousand, eight hundred twenty-one".