21019017043 has 2 divisors, whose sum is σ = 21019017044. Its totient is φ = 21019017042.

The previous prime is 21019017037. The next prime is 21019017067. The reversal of 21019017043 is 34071091012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21019017043 - 2⁹ = 21019016531 is a prime.

It is not a weakly prime, because it can be changed into another prime (21019017143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10509508521 + 10509508522.

It is an arithmetic number, because the mean of its divisors is an integer number (10509508522).

Almost surely, 2^21019017043 is an apocalyptic number.

21019017043 is a deficient number, since it is larger than the sum of its proper divisors (1).

21019017043 is an equidigital number, since it uses as much as digits as its factorization.

21019017043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 28.

The spelling of 21019017043 in words is "twenty-one billion, nineteen million, seventeen thousand, forty-three".