2101397281 has 3 divisors (see below), whose sum is σ = 2101443123. Its totient is φ = 2101351440.

The previous prime is 2101397273. The next prime is 2101397293. The reversal of 2101397281 is 1827931012.

The square root of 2101397281 is 45841.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1398086881 + 703310400 = 37391^2 + 26520^2 .

It is not a de Polignac number, because 2101397281 - 2³ = 2101397273 is a prime.

It is a super-2 number, since 2×2101397281² = 8831741065188385922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2101397261) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 22921 + ... + 68761.

It is an arithmetic number, because the mean of its divisors is an integer number (700481041).

Almost surely, 2^2101397281 is an apocalyptic number.

2101397281 is the 45841-st square number.

2101397281 is the 22921-st centered octagonal number.

It is an amenable number.

2101397281 is a deficient number, since it is larger than the sum of its proper divisors (45842).

2101397281 is an frugal number, since it uses more digits than its factorization.

2101397281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91682 (or 45841 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 34.

The cubic root of 2101397281 is about 1280.8631224838.

The spelling of 2101397281 in words is "two billion, one hundred one million, three hundred ninety-seven thousand, two hundred eighty-one".