21458231693 has 4 divisors (see below), whose sum is σ = 21469076640. Its totient is φ = 21447386748.

The previous prime is 21458231689. The next prime is 21458231719. The reversal of 21458231693 is 39613285412.

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 a cyclic number.

It is not a de Polignac number, because 21458231693 - 2² = 21458231689 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 (21458231393) 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, 5419505 + ... + 5423462.

It is an arithmetic number, because the mean of its divisors is an integer number (5367269160).

Almost surely, 2^21458231693 is an apocalyptic number.

It is an amenable number.

21458231693 is a deficient number, since it is larger than the sum of its proper divisors (10844947).

21458231693 is a wasteful number, since it uses less digits than its factorization.

21458231693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10844946.

The product of its digits is 311040, while the sum is 44.

The spelling of 21458231693 in words is "twenty-one billion, four hundred fifty-eight million, two hundred thirty-one thousand, six hundred ninety-three".