775330921 has 4 divisors (see below), whose sum is σ = 802066500. Its totient is φ = 748595344.

The previous prime is 775330909. The next prime is 775330931. The reversal of 775330921 is 129033577.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 129033577 = 151 ⋅854527.

It can be written as a sum of positive squares in 2 ways, for example, as 452625625 + 322705296 = 21275^2 + 17964^2 .

It is a cyclic number.

It is not a de Polignac number, because 775330921 - 2⁵ = 775330889 is a prime.

It is a super-2 number, since 2×775330921² = 1202276074117416482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (775330931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13367746 + ... + 13367803.

It is an arithmetic number, because the mean of its divisors is an integer number (200516625).

Almost surely, 2^775330921 is an apocalyptic number.

It is an amenable number.

775330921 is a deficient number, since it is larger than the sum of its proper divisors (26735579).

775330921 is a wasteful number, since it uses less digits than its factorization.

775330921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26735578.

The product of its (nonzero) digits is 39690, while the sum is 37.

The square root of 775330921 is about 27844.7646964380. The cubic root of 775330921 is about 918.6759944339.

The spelling of 775330921 in words is "seven hundred seventy-five million, three hundred thirty thousand, nine hundred twenty-one".