1540210221 has 40 divisors (see below), whose sum is σ = 2533159200. Its totient is φ = 924838560.

The previous prime is 1540210219. The next prime is 1540210241. The reversal of 1540210221 is 1220120451.

1540210221 is a `hidden beast` number, since 1 + 540 + 2 + 102 + 21 = 666.

It is not a de Polignac number, because 1540210221 - 2¹ = 1540210219 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1540210194 and 1540210203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1540210241) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 89190 + ... + 105048.

It is an arithmetic number, because the mean of its divisors is an integer number (63328980).

Almost surely, 2^1540210221 is an apocalyptic number.

1540210221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1540210221 is a deficient number, since it is larger than the sum of its proper divisors (992948979).

1540210221 is a wasteful number, since it uses less digits than its factorization.

1540210221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15991 (or 15982 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 1540210221 is about 39245.5121128518. The cubic root of 1540210221 is about 1154.8528940662.

Adding to 1540210221 its reverse (1220120451), we get a palindrome (2760330672).

The spelling of 1540210221 in words is "one billion, five hundred forty million, two hundred ten thousand, two hundred twenty-one".