215001540 has 288 divisors, whose sum is σ = 755104896. Its totient is φ = 51010560.

The previous prime is 215001509. The next prime is 215001541. The reversal of 215001540 is 45100512.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215001541) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2590339 + ... + 2590421.

It is an arithmetic number, because the mean of its divisors is an integer number (2621892).

Almost surely, 2^215001540 is an apocalyptic number.

215001540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215001540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (377552448).

215001540 is an abundant number, since it is smaller than the sum of its proper divisors (540103356).

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

215001540 is a wasteful number, since it uses less digits than its factorization.

215001540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 215001540 is about 14662.9308120853. The cubic root of 215001540 is about 599.0740718301.

The spelling of 215001540 in words is "two hundred fifteen million, one thousand, five hundred forty".