20877551 has 2 divisors, whose sum is σ = 20877552. Its totient is φ = 20877550.

The previous prime is 20877517. The next prime is 20877553. The reversal of 20877551 is 15577802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20877551 - 2¹⁴ = 20861167 is a prime.

Together with 20877553, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20877553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10438775 + 10438776.

It is an arithmetic number, because the mean of its divisors is an integer number (10438776).

Almost surely, 2^20877551 is an apocalyptic number.

20877551 is a deficient number, since it is larger than the sum of its proper divisors (1).

20877551 is an equidigital number, since it uses as much as digits as its factorization.

20877551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19600, while the sum is 35.

The square root of 20877551 is about 4569.1958811152. The cubic root of 20877551 is about 275.3551378680.

The spelling of 20877551 in words is "twenty million, eight hundred seventy-seven thousand, five hundred fifty-one".