21298177673 has 2 divisors, whose sum is σ = 21298177674. Its totient is φ = 21298177672.

The previous prime is 21298177631. The next prime is 21298177727. The reversal of 21298177673 is 37677189212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21273097609 + 25080064 = 145853^2 + 5008^2 .

It is a cyclic number.

It is not a de Polignac number, because 21298177673 - 2¹⁶ = 21298112137 is a prime.

It is a super-2 number, since 2×21298177673² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21298177603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10649088836 + 10649088837.

It is an arithmetic number, because the mean of its divisors is an integer number (10649088837).

Almost surely, 2^21298177673 is an apocalyptic number.

It is an amenable number.

21298177673 is a deficient number, since it is larger than the sum of its proper divisors (1).

21298177673 is an equidigital number, since it uses as much as digits as its factorization.

21298177673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1778112, while the sum is 53.

The spelling of 21298177673 in words is "twenty-one billion, two hundred ninety-eight million, one hundred seventy-seven thousand, six hundred seventy-three".