999229621 has 32 divisors (see below), whose sum is σ = 1164306528. Its totient is φ = 849346560.

The previous prime is 999229529. The next prime is 999229633. The reversal of 999229621 is 126922999.

It can be written as a sum of positive squares in 16 ways, for example, as 3132900 + 996096721 = 1770^2 + 31561^2 .

It is a 11-Lehmer number, since φ(999229621) divides (999229621-1)¹¹.

It is a cyclic number.

It is not a de Polignac number, because 999229621 - 2⁹ = 999229109 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 (999229661) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3887925 + ... + 3888181.

It is an arithmetic number, because the mean of its divisors is an integer number (36384579).

Almost surely, 2^999229621 is an apocalyptic number.

It is an amenable number.

999229621 is a deficient number, since it is larger than the sum of its proper divisors (165076907).

999229621 is a wasteful number, since it uses less digits than its factorization.

999229621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 601.

The product of its digits is 314928, while the sum is 49.

The square root of 999229621 is about 31610.5934933212. The cubic root of 999229621 is about 999.7431410291.

The spelling of 999229621 in words is "nine hundred ninety-nine million, two hundred twenty-nine thousand, six hundred twenty-one".