216540477 has 12 divisors (see below), whose sum is σ = 323566620. Its totient is φ = 139382208.

The previous prime is 216540451. The next prime is 216540491. The reversal of 216540477 is 774045612.

216540477 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 48734361 + 167806116 = 6981^2 + 12954^2 .

It is not a de Polignac number, because 216540477 - 2⁶ = 216540413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216540977) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 414568 + ... + 415089.

It is an arithmetic number, because the mean of its divisors is an integer number (26963885).

Almost surely, 2^216540477 is an apocalyptic number.

It is an amenable number.

216540477 is a deficient number, since it is larger than the sum of its proper divisors (107026143).

216540477 is a wasteful number, since it uses less digits than its factorization.

216540477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 829692 (or 829689 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

The square root of 216540477 is about 14715.3143697306. The cubic root of 216540477 is about 600.5000248428.

The spelling of 216540477 in words is "two hundred sixteen million, five hundred forty thousand, four hundred seventy-seven".