764441821 has 12 divisors (see below), whose sum is σ = 904891036. Its totient is φ = 641488320.

The previous prime is 764441809. The next prime is 764441837. The reversal of 764441821 is 128144467.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 315595225 + 448846596 = 17765^2 + 21186^2 .

It is not a de Polignac number, because 764441821 - 2⁵ = 764441789 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 (764441891) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 241416 + ... + 244561.

Almost surely, 2^764441821 is an apocalyptic number.

It is an amenable number.

764441821 is a deficient number, since it is larger than the sum of its proper divisors (140449215).

764441821 is a wasteful number, since it uses less digits than its factorization.

764441821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486012 (or 486001 counting only the distinct ones).

The product of its digits is 43008, while the sum is 37.

The square root of 764441821 is about 27648.5410284159. The cubic root of 764441821 is about 914.3549340764.

The spelling of 764441821 in words is "seven hundred sixty-four million, four hundred forty-one thousand, eight hundred twenty-one".