215266947840 has 1440 divisors, whose sum is σ = 944500677120. Its totient is φ = 45721387008.

The previous prime is 215266947817. The next prime is 215266947881. The reversal of 215266947840 is 48749662512.

215266947840 is a `hidden beast` number, since 2 + 1 + 526 + 6 + 9 + 4 + 78 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (1440).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 923892364 + ... + 923892596.

It is an arithmetic number, because the mean of its divisors is an integer number (655903248).

Almost surely, 2^215266947840 is an apocalyptic number.

215266947840 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 215266947840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (472250338560).

215266947840 is an abundant number, since it is smaller than the sum of its proper divisors (729233729280).

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

215266947840 is a wasteful number, since it uses less digits than its factorization.

215266947840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359 (or 336 counting only the distinct ones).

The product of its (nonzero) digits is 5806080, while the sum is 54.

The spelling of 215266947840 in words is "two hundred fifteen billion, two hundred sixty-six million, nine hundred forty-seven thousand, eight hundred forty".