21152516154331 has 4 divisors (see below), whose sum is σ = 21152528042464. Its totient is φ = 21152504266200.

The previous prime is 21152516154307. The next prime is 21152516154433. The reversal of 21152516154331 is 13345161525112.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21152516154331 - 2¹¹ = 21152516152283 is a prime.

It is a super-2 number, since 2×21152516154331² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21152516154031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2676300 + ... + 7033321.

It is an arithmetic number, because the mean of its divisors is an integer number (5288132010616).

Almost surely, 2^{21152516154331} is an apocalyptic number.

21152516154331 is a deficient number, since it is larger than the sum of its proper divisors (11888133).

21152516154331 is an equidigital number, since it uses as much as digits as its factorization.

21152516154331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11888132.

The product of its digits is 108000, while the sum is 40.

Adding to 21152516154331 its reverse (13345161525112), we get a palindrome (34497677679443).

The spelling of 21152516154331 in words is "twenty-one trillion, one hundred fifty-two billion, five hundred sixteen million, one hundred fifty-four thousand, three hundred thirty-one".