21394039903 has 2 divisors, whose sum is σ = 21394039904. Its totient is φ = 21394039902.

The previous prime is 21394039897. The next prime is 21394039981. The reversal of 21394039903 is 30993049312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21394039903 - 2⁵ = 21394039871 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21394039903.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21394039103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10697019951 + 10697019952.

It is an arithmetic number, because the mean of its divisors is an integer number (10697019952).

Almost surely, 2^21394039903 is an apocalyptic number.

21394039903 is a deficient number, since it is larger than the sum of its proper divisors (1).

21394039903 is an equidigital number, since it uses as much as digits as its factorization.

21394039903 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 157464, while the sum is 43.

The spelling of 21394039903 in words is "twenty-one billion, three hundred ninety-four million, thirty-nine thousand, nine hundred three".