21152515440506 has 8 divisors (see below), whose sum is σ = 31729091948064. Its totient is φ = 10576151457820.

The previous prime is 21152515440421. The next prime is 21152515440523. The reversal of 21152515440506 is 60504451525112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52882160 + ... + 53280651.

It is an arithmetic number, because the mean of its divisors is an integer number (3966136493508).

Almost surely, 2^{21152515440506} is an apocalyptic number.

21152515440506 is a deficient number, since it is larger than the sum of its proper divisors (10576576507558).

21152515440506 is a wasteful number, since it uses less digits than its factorization.

21152515440506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106262436.

The product of its (nonzero) digits is 240000, while the sum is 41.

Adding to 21152515440506 its reverse (60504451525112), we get a palindrome (81656966965618).

The spelling of 21152515440506 in words is "twenty-one trillion, one hundred fifty-two billion, five hundred fifteen million, four hundred forty thousand, five hundred six".