83971021643 has 2 divisors, whose sum is σ = 83971021644. Its totient is φ = 83971021642.

The previous prime is 83971021639. The next prime is 83971021657. The reversal of 83971021643 is 34612017938.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 83971021643 - 2² = 83971021639 is a prime.

It is a super-2 number, since 2×83971021643² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 83971021594 and 83971021603.

It is not a weakly prime, because it can be changed into another prime (83971021843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41985510821 + 41985510822.

It is an arithmetic number, because the mean of its divisors is an integer number (41985510822).

Almost surely, 2^83971021643 is an apocalyptic number.

83971021643 is a deficient number, since it is larger than the sum of its proper divisors (1).

83971021643 is an equidigital number, since it uses as much as digits as its factorization.

83971021643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 44.

The spelling of 83971021643 in words is "eighty-three billion, nine hundred seventy-one million, twenty-one thousand, six hundred forty-three".