21376638771839 has 16 divisors (see below), whose sum is σ = 23816337793920. Its totient is φ = 19050646621440.

The previous prime is 21376638771779. The next prime is 21376638771899. The reversal of 21376638771839 is 93817783667312.

It is an interprime number because it is at equal distance from previous prime (21376638771779) and next prime (21376638771899).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21376638771839 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 (21376638771899) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4157819 + ... + 7748595.

It is an arithmetic number, because the mean of its divisors is an integer number (1488521112120).

Almost surely, 2^{21376638771839} is an apocalyptic number.

21376638771839 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21376638771839 is a deficient number, since it is larger than the sum of its proper divisors (2439699022081).

21376638771839 is a wasteful number, since it uses less digits than its factorization.

21376638771839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3606610.

The product of its digits is 384072192, while the sum is 71.

The spelling of 21376638771839 in words is "twenty-one trillion, three hundred seventy-six billion, six hundred thirty-eight million, seven hundred seventy-one thousand, eight hundred thirty-nine".