21673577 has 2 divisors, whose sum is σ = 21673578. Its totient is φ = 21673576.

The previous prime is 21673573. The next prime is 21673633. The reversal of 21673577 is 77537612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21058921 + 614656 = 4589^2 + 784^2 .

It is a cyclic number.

It is not a de Polignac number, because 21673577 - 2² = 21673573 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21673577.

It is not a weakly prime, because it can be changed into another prime (21673573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10836788 + 10836789.

It is an arithmetic number, because the mean of its divisors is an integer number (10836789).

Almost surely, 2^21673577 is an apocalyptic number.

It is an amenable number.

21673577 is a deficient number, since it is larger than the sum of its proper divisors (1).

21673577 is an equidigital number, since it uses as much as digits as its factorization.

21673577 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 61740, while the sum is 38.

The square root of 21673577 is about 4655.4889109523. The cubic root of 21673577 is about 278.8111884819.

The spelling of 21673577 in words is "twenty-one million, six hundred seventy-three thousand, five hundred seventy-seven".