215641240 has 32 divisors (see below), whose sum is σ = 489654000. Its totient is φ = 85463424.

The previous prime is 215641229. The next prime is 215641253. The reversal of 215641240 is 42146512.

It is a happy number.

215641240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×215641240² = 93002288777475200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20370 + ... + 29089.

Almost surely, 2^215641240 is an apocalyptic number.

215641240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215641240 is an abundant number, since it is smaller than the sum of its proper divisors (274012760).

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

215641240 is a wasteful number, since it uses less digits than its factorization.

215641240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49579 (or 49575 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 215641240 is about 14684.7281214192. The cubic root of 215641240 is about 599.6676307333.

Adding to 215641240 its reverse (42146512), we get a palindrome (257787752).

The spelling of 215641240 in words is "two hundred fifteen million, six hundred forty-one thousand, two hundred forty".