75801821 has 2 divisors, whose sum is σ = 75801822. Its totient is φ = 75801820.

The previous prime is 75801809. The next prime is 75801823. The reversal of 75801821 is 12810857.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67010596 + 8791225 = 8186^2 + 2965^2 .

It is an emirp because it is prime and its reverse (12810857) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 75801821 - 2¹⁸ = 75539677 is a prime.

It is a Sophie Germain prime.

Together with 75801823, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (75801823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37900910 + 37900911.

It is an arithmetic number, because the mean of its divisors is an integer number (37900911).

Almost surely, 2^75801821 is an apocalyptic number.

It is an amenable number.

75801821 is a deficient number, since it is larger than the sum of its proper divisors (1).

75801821 is an equidigital number, since it uses as much as digits as its factorization.

75801821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 75801821 is about 8706.4241224512. The cubic root of 75801821 is about 423.2138575495.

The spelling of 75801821 in words is "seventy-five million, eight hundred one thousand, eight hundred twenty-one".