216139440 has 320 divisors, whose sum is σ = 799948800. Its totient is φ = 47692800.

The previous prime is 216139439. The next prime is 216139481. The reversal of 216139440 is 44931612.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 216139398 and 216139407.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1554891 + ... + 1555029.

It is an arithmetic number, because the mean of its divisors is an integer number (2499840).

Almost surely, 2^216139440 is an apocalyptic number.

216139440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216139440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (399974400).

216139440 is an abundant number, since it is smaller than the sum of its proper divisors (583809360).

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

216139440 is a wasteful number, since it uses less digits than its factorization.

216139440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216 (or 210 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 216139440 is about 14701.6815364774. The cubic root of 216139440 is about 600.1290833383.

It can be divided in two parts, 216 and 139440, that added together give a triangular number (139656 = T₅₂₈).

The spelling of 216139440 in words is "two hundred sixteen million, one hundred thirty-nine thousand, four hundred forty".