83121351247421 has 4 divisors (see below), whose sum is σ = 84889890635712. Its totient is φ = 81352811859132.

The previous prime is 83121351247393. The next prime is 83121351247471. The reversal of 83121351247421 is 12474215312138.

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 83121351247421 - 2⁶ = 83121351247357 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 (83121351247471) 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, 884269694075 + ... + 884269694168.

It is an arithmetic number, because the mean of its divisors is an integer number (21222472658928).

Almost surely, 2^{83121351247421} is an apocalyptic number.

It is an amenable number.

83121351247421 is a deficient number, since it is larger than the sum of its proper divisors (1768539388291).

83121351247421 is a wasteful number, since it uses less digits than its factorization.

83121351247421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1768539388290.

The product of its digits is 322560, while the sum is 44.

Adding to 83121351247421 its reverse (12474215312138), we get a palindrome (95595566559559).

The spelling of 83121351247421 in words is "eighty-three trillion, one hundred twenty-one billion, three hundred fifty-one million, two hundred forty-seven thousand, four hundred twenty-one".