215040921 has 16 divisors (see below), whose sum is σ = 294028800. Its totient is φ = 139749120.

The previous prime is 215040901. The next prime is 215040937. The reversal of 215040921 is 129040512.

It is not a de Polignac number, because 215040921 - 2⁶ = 215040857 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 215040891 and 215040900.

It is not an unprimeable number, because it can be changed into a prime (215040901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15480 + ... + 25878.

It is an arithmetic number, because the mean of its divisors is an integer number (18376800).

Almost surely, 2^215040921 is an apocalyptic number.

It is an amenable number.

215040921 is a deficient number, since it is larger than the sum of its proper divisors (78987879).

215040921 is a wasteful number, since it uses less digits than its factorization.

215040921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10576.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 215040921 is about 14664.2736267433. The cubic root of 215040921 is about 599.1106462902.

It can be divided in two parts, 2150 and 40921, that added together give a triangular number (43071 = T₂₉₃).

The spelling of 215040921 in words is "two hundred fifteen million, forty thousand, nine hundred twenty-one".