216021455 has 16 divisors (see below), whose sum is σ = 280892640. Its totient is φ = 158537088.

The previous prime is 216021437. The next prime is 216021457. The reversal of 216021455 is 554120612.

It is a cyclic number.

It is not a de Polignac number, because 216021455 - 2⁶ = 216021391 is a prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216021457) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 401 + ... + 20789.

It is an arithmetic number, because the mean of its divisors is an integer number (17555790).

Almost surely, 2^216021455 is an apocalyptic number.

216021455 is a deficient number, since it is larger than the sum of its proper divisors (64871185).

216021455 is a wasteful number, since it uses less digits than its factorization.

216021455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20570.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 216021455 is about 14697.6683524973. The cubic root of 216021455 is about 600.0198650830.

The spelling of 216021455 in words is "two hundred sixteen million, twenty-one thousand, four hundred fifty-five".