215121510240 has 192 divisors, whose sum is σ = 834009716736. Its totient is φ = 45388265472.

The previous prime is 215121510229. The next prime is 215121510251. The reversal of 215121510240 is 42015121512.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (215121510229) and next prime (215121510251).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 215121510240.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2418792 + ... + 2506151.

It is an arithmetic number, because the mean of its divisors is an integer number (4343800608).

Almost surely, 2^215121510240 is an apocalyptic number.

215121510240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215121510240 is an abundant number, since it is smaller than the sum of its proper divisors (618888206496).

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

215121510240 is a wasteful number, since it uses less digits than its factorization.

215121510240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4924981 (or 4924973 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 24.

Adding to 215121510240 its reverse (42015121512), we get a palindrome (257136631752).

The spelling of 215121510240 in words is "two hundred fifteen billion, one hundred twenty-one million, five hundred ten thousand, two hundred forty".