216631240 has 32 divisors (see below), whose sum is σ = 557052480. Its totient is φ = 74273472.

The previous prime is 216631229. The next prime is 216631243. The reversal of 216631240 is 42136612.

216631240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (216631243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 386562 + ... + 387121.

It is an arithmetic number, because the mean of its divisors is an integer number (17407890).

Almost surely, 2^216631240 is an apocalyptic number.

216631240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216631240 is an abundant number, since it is smaller than the sum of its proper divisors (340421240).

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

216631240 is a wasteful number, since it uses less digits than its factorization.

216631240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 773701 (or 773697 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 216631240 is about 14718.3980106532. The cubic root of 216631240 is about 600.5839130397.

Adding to 216631240 its reverse (42136612), we get a palindrome (258767852).

The spelling of 216631240 in words is "two hundred sixteen million, six hundred thirty-one thousand, two hundred forty".