2101976721 has 12 divisors (see below), whose sum is σ = 3269741748. Its totient is φ = 1293524064.

The previous prime is 2101976699. The next prime is 2101976749. The reversal of 2101976721 is 1276791012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 552767121 + 1549209600 = 23511^2 + 39360^2 .

It is not a de Polignac number, because 2101976721 - 2⁵ = 2101976689 is a prime.

It is a super-2 number, since 2×2101976721² = 8836612271251823682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2101976761) 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, 8982690 + ... + 8982923.

It is an arithmetic number, because the mean of its divisors is an integer number (272478479).

Almost surely, 2^2101976721 is an apocalyptic number.

It is an amenable number.

2101976721 is a deficient number, since it is larger than the sum of its proper divisors (1167765027).

2101976721 is a wasteful number, since it uses less digits than its factorization.

2101976721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17965632 (or 17965629 counting only the distinct ones).

The product of its (nonzero) digits is 10584, while the sum is 36.

The square root of 2101976721 is about 45847.3196708379. The cubic root of 2101976721 is about 1280.9808402087.

The spelling of 2101976721 in words is "two billion, one hundred one million, nine hundred seventy-six thousand, seven hundred twenty-one".