216781420 has 48 divisors (see below), whose sum is σ = 463988448. Its totient is φ = 85063680.

The previous prime is 216781387. The next prime is 216781427. The reversal of 216781420 is 24187612.

It is not an unprimeable number, because it can be changed into a prime (216781427) 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, 253714 + ... + 254566.

It is an arithmetic number, because the mean of its divisors is an integer number (9666426).

Almost surely, 2^216781420 is an apocalyptic number.

216781420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216781420 is an abundant number, since it is smaller than the sum of its proper divisors (247207028).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216781420 is a wasteful number, since it uses less digits than its factorization.

216781420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1090 (or 1088 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 216781420 is about 14723.4989048120. The cubic root of 216781420 is about 600.7226662767.

The spelling of 216781420 in words is "two hundred sixteen million, seven hundred eighty-one thousand, four hundred twenty".