921022821 has 12 divisors (see below), whose sum is σ = 1408623372. Its totient is φ = 577896576.

The previous prime is 921022813. The next prime is 921022829. The reversal of 921022821 is 128220129.

It is an interprime number because it is at equal distance from previous prime (921022813) and next prime (921022829).

It can be written as a sum of positive squares in 2 ways, for example, as 790172100 + 130850721 = 28110^2 + 11439^2 .

It is not a de Polignac number, because 921022821 - 2³ = 921022813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (921022829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3009726 + ... + 3010031.

It is an arithmetic number, because the mean of its divisors is an integer number (117385281).

Almost surely, 2^921022821 is an apocalyptic number.

It is an amenable number.

921022821 is a deficient number, since it is larger than the sum of its proper divisors (487600551).

921022821 is a wasteful number, since it uses less digits than its factorization.

921022821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6019780 (or 6019777 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 921022821 is about 30348.3577974163. The cubic root of 921022821 is about 972.9491218163.

The spelling of 921022821 in words is "nine hundred twenty-one million, twenty-two thousand, eight hundred twenty-one".