216711457 has 4 divisors (see below), whose sum is σ = 219454720. Its totient is φ = 213968196.

The previous prime is 216711449. The next prime is 216711493. The reversal of 216711457 is 754117612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 216711457 - 2³ = 216711449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216711437) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1371513 + ... + 1371670.

It is an arithmetic number, because the mean of its divisors is an integer number (54863680).

Almost surely, 2^216711457 is an apocalyptic number.

It is an amenable number.

216711457 is a deficient number, since it is larger than the sum of its proper divisors (2743263).

216711457 is an equidigital number, since it uses as much as digits as its factorization.

216711457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2743262.

The product of its digits is 11760, while the sum is 34.

The square root of 216711457 is about 14721.1228172310. The cubic root of 216711457 is about 600.6580345352.

The spelling of 216711457 in words is "two hundred sixteen million, seven hundred eleven thousand, four hundred fifty-seven".