278021216 has 72 divisors (see below), whose sum is σ = 612337320. Its totient is φ = 124129280.

The previous prime is 278021209. The next prime is 278021221. The reversal of 278021216 is 612120872.

It is a super-2 number, since 2×278021216² = 154591593092237312, which contains 22 as substring.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 227840 + ... + 229056.

It is an arithmetic number, because the mean of its divisors is an integer number (8504685).

Almost surely, 2^278021216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 278021216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (306168660).

278021216 is an abundant number, since it is smaller than the sum of its proper divisors (334316104).

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

278021216 is a wasteful number, since it uses less digits than its factorization.

278021216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1308 (or 1289 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 278021216 is about 16673.9682139555. The cubic root of 278021216 is about 652.6684902248.

The spelling of 278021216 in words is "two hundred seventy-eight million, twenty-one thousand, two hundred sixteen".