21395677 has 2 divisors, whose sum is σ = 21395678. Its totient is φ = 21395676.

The previous prime is 21395663. The next prime is 21395723. The reversal of 21395677 is 77659312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21335161 + 60516 = 4619^2 + 246^2 .

It is a cyclic number.

It is not a de Polignac number, because 21395677 - 2¹⁵ = 21362909 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21395617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10697838 + 10697839.

It is an arithmetic number, because the mean of its divisors is an integer number (10697839).

Almost surely, 2^21395677 is an apocalyptic number.

It is an amenable number.

21395677 is a deficient number, since it is larger than the sum of its proper divisors (1).

21395677 is an equidigital number, since it uses as much as digits as its factorization.

21395677 is an evil number, because the sum of its binary digits is even.

The product of its digits is 79380, while the sum is 40.

The square root of 21395677 is about 4625.5461299181. The cubic root of 21395677 is about 277.6144137679.

The spelling of 21395677 in words is "twenty-one million, three hundred ninety-five thousand, six hundred seventy-seven".