215040744661 has 4 divisors (see below), whose sum is σ = 215285945932. Its totient is φ = 214795543392.

The previous prime is 215040744601. The next prime is 215040744679. The reversal of 215040744661 is 166447040512.

215040744661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 189494796100 + 25545948561 = 435310^2 + 159831^2 .

It is a cyclic number.

It is not a de Polignac number, because 215040744661 - 2¹¹ = 215040742613 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 (215040744601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122599320 + ... + 122601073.

It is an arithmetic number, because the mean of its divisors is an integer number (53821486483).

Almost surely, 2^215040744661 is an apocalyptic number.

It is an amenable number.

215040744661 is a deficient number, since it is larger than the sum of its proper divisors (245201271).

215040744661 is an equidigital number, since it uses as much as digits as its factorization.

215040744661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245201270.

The product of its (nonzero) digits is 161280, while the sum is 40.

The spelling of 215040744661 in words is "two hundred fifteen billion, forty million, seven hundred forty-four thousand, six hundred sixty-one".