21501551532413 has 6 divisors (see below), whose sum is σ = 21693514649274. Its totient is φ = 21311272302656.

The previous prime is 21501551532403. The next prime is 21501551532431. The reversal of 21501551532413 is 31423515510512.

It can be written as a sum of positive squares in 3 ways, for example, as 24286728964 + 21477264803449 = 155842^2 + 4634357^2 .

It is not a de Polignac number, because 21501551532413 - 2¹⁶ = 21501551466877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21501551532403) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 841930670 + ... + 841956207.

It is an arithmetic number, because the mean of its divisors is an integer number (3615585774879).

Almost surely, 2^{21501551532413} is an apocalyptic number.

It is an amenable number.

21501551532413 is a deficient number, since it is larger than the sum of its proper divisors (191963116861).

21501551532413 is an equidigital number, since it uses as much as digits as its factorization.

21501551532413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1683887103 (or 1683886990 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 38.

The spelling of 21501551532413 in words is "twenty-one trillion, five hundred one billion, five hundred fifty-one million, five hundred thirty-two thousand, four hundred thirteen".