2016997921 has 9 divisors (see below), whose sum is σ = 2042417331. Its totient is φ = 1991892672.

The previous prime is 2016997867. The next prime is 2016997999. The reversal of 2016997921 is 1297996102.

It is a happy number.

The square root of 2016997921 is 44911.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 905709025 + 1111288896 = 30095^2 + 33336^2 .

It is not a de Polignac number, because 2016997921 - 2¹⁹ = 2016473633 is a prime.

It is a super-2 number, since 2×2016997921² = 8136561226636644482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2016997721) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4356136 + ... + 4356598.

It is an arithmetic number, because the mean of its divisors is an integer number (226935259).

Almost surely, 2^2016997921 is an apocalyptic number.

2016997921 is the 44911-st square number.

2016997921 is the 22456-th centered octagonal number.

It is an amenable number.

2016997921 is a deficient number, since it is larger than the sum of its proper divisors (25419410).

2016997921 is an frugal number, since it uses more digits than its factorization.

2016997921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1120 (or 560 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 46.

The cubic root of 2016997921 is about 1263.4803252237.

The spelling of 2016997921 in words is "two billion, sixteen million, nine hundred ninety-seven thousand, nine hundred twenty-one".