215638113240 has 96 divisors (see below), whose sum is σ = 764535142800. Its totient is φ = 52275905280.

The previous prime is 215638113227. The next prime is 215638113253. The reversal of 215638113240 is 42311836512.

215638113240 is a `hidden beast` number, since 2 + 1 + 5 + 638 + 1 + 13 + 2 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (215638113227) and next prime (215638113253).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 215638113195 and 215638113204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27223075 + ... + 27230994.

Almost surely, 2^215638113240 is an apocalyptic number.

215638113240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215638113240 is an abundant number, since it is smaller than the sum of its proper divisors (548897029560).

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

215638113240 is a wasteful number, since it uses less digits than its factorization.

215638113240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54454097 (or 54454090 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

Adding to 215638113240 its reverse (42311836512), we get a palindrome (257949949752).

The spelling of 215638113240 in words is "two hundred fifteen billion, six hundred thirty-eight million, one hundred thirteen thousand, two hundred forty".