215678420 has 12 divisors (see below), whose sum is σ = 452924724. Its totient is φ = 86271360.

The previous prime is 215678413. The next prime is 215678431. The reversal of 215678420 is 24876512.

It can be written as a sum of positive squares in 2 ways, for example, as 81072016 + 134606404 = 9004^2 + 11602^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5391941 + ... + 5391980.

It is an arithmetic number, because the mean of its divisors is an integer number (37743727).

Almost surely, 2^215678420 is an apocalyptic number.

215678420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215678420 is an abundant number, since it is smaller than the sum of its proper divisors (237246304).

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

215678420 is a wasteful number, since it uses less digits than its factorization.

215678420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10783930 (or 10783928 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 35.

The square root of 215678420 is about 14685.9940078975. The cubic root of 215678420 is about 599.7020928508.

The spelling of 215678420 in words is "two hundred fifteen million, six hundred seventy-eight thousand, four hundred twenty".