21177504079 has 2 divisors, whose sum is σ = 21177504080. Its totient is φ = 21177504078.

The previous prime is 21177504067. The next prime is 21177504109. The reversal of 21177504079 is 97040577112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21177504079 - 2¹³ = 21177495887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21177504059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10588752039 + 10588752040.

It is an arithmetic number, because the mean of its divisors is an integer number (10588752040).

Almost surely, 2^21177504079 is an apocalyptic number.

21177504079 is a deficient number, since it is larger than the sum of its proper divisors (1).

21177504079 is an equidigital number, since it uses as much as digits as its factorization.

21177504079 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 123480, while the sum is 43.

The spelling of 21177504079 in words is "twenty-one billion, one hundred seventy-seven million, five hundred four thousand, seventy-nine".