21407677 has 2 divisors, whose sum is σ = 21407678. Its totient is φ = 21407676.

The previous prime is 21407671. The next prime is 21407681. The reversal of 21407677 is 77670412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19175641 + 2232036 = 4379^2 + 1494^2 .

It is a cyclic number.

It is not a de Polignac number, because 21407677 - 2³ = 21407669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21407671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10703838 + 10703839.

It is an arithmetic number, because the mean of its divisors is an integer number (10703839).

Almost surely, 2^21407677 is an apocalyptic number.

It is an amenable number.

21407677 is a deficient number, since it is larger than the sum of its proper divisors (1).

21407677 is an equidigital number, since it uses as much as digits as its factorization.

21407677 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16464, while the sum is 34.

The square root of 21407677 is about 4626.8430922174. The cubic root of 21407677 is about 277.6663050970. Note that the first 3 decimals are identical.

The spelling of 21407677 in words is "twenty-one million, four hundred seven thousand, six hundred seventy-seven".