21138704077 has 8 divisors (see below), whose sum is σ = 22408228800. Its totient is φ = 19872076224.

The previous prime is 21138704051. The next prime is 21138704123. The reversal of 21138704077 is 77040783112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21138704077 - 2¹⁹ = 21138179789 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 (21138704017) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 709177 + ... + 738382.

It is an arithmetic number, because the mean of its divisors is an integer number (2801028600).

Almost surely, 2^21138704077 is an apocalyptic number.

It is an amenable number.

21138704077 is a deficient number, since it is larger than the sum of its proper divisors (1269524723).

21138704077 is a wasteful number, since it uses less digits than its factorization.

21138704077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1448435.

The product of its (nonzero) digits is 65856, while the sum is 40.

The spelling of 21138704077 in words is "twenty-one billion, one hundred thirty-eight million, seven hundred four thousand, seventy-seven".