216657953 has 8 divisors (see below), whose sum is σ = 226435776. Its totient is φ = 206910000.

The previous prime is 216657949. The next prime is 216657983. The reversal of 216657953 is 359756612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 216657953 - 2² = 216657949 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216657913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8078 + ... + 22328.

It is an arithmetic number, because the mean of its divisors is an integer number (28304472).

Almost surely, 2^216657953 is an apocalyptic number.

216657953 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

216657953 is a deficient number, since it is larger than the sum of its proper divisors (9777823).

216657953 is a wasteful number, since it uses less digits than its factorization.

216657953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14935.

The product of its digits is 340200, while the sum is 44.

The square root of 216657953 is about 14719.3054523643. The cubic root of 216657953 is about 600.6085982124.

The spelling of 216657953 in words is "two hundred sixteen million, six hundred fifty-seven thousand, nine hundred fifty-three".