21346521501 has 4 divisors (see below), whose sum is σ = 28462028672. Its totient is φ = 14231014332.

The previous prime is 21346521487. The next prime is 21346521517. The reversal of 21346521501 is 10512564312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21346521501 - 2⁹ = 21346520989 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 (21346521571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3557753581 + ... + 3557753586.

It is an arithmetic number, because the mean of its divisors is an integer number (7115507168).

Almost surely, 2^21346521501 is an apocalyptic number.

It is an amenable number.

21346521501 is a deficient number, since it is larger than the sum of its proper divisors (7115507171).

21346521501 is an equidigital number, since it uses as much as digits as its factorization.

21346521501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7115507170.

The product of its (nonzero) digits is 7200, while the sum is 30.

The spelling of 21346521501 in words is "twenty-one billion, three hundred forty-six million, five hundred twenty-one thousand, five hundred one".