20977571 has 2 divisors, whose sum is σ = 20977572. Its totient is φ = 20977570.

The previous prime is 20977543. The next prime is 20977601. The reversal of 20977571 is 17577902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20977571 - 2¹⁰ = 20976547 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20977531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10488785 + 10488786.

It is an arithmetic number, because the mean of its divisors is an integer number (10488786).

Almost surely, 2^20977571 is an apocalyptic number.

20977571 is a deficient number, since it is larger than the sum of its proper divisors (1).

20977571 is an equidigital number, since it uses as much as digits as its factorization.

20977571 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30870, while the sum is 38.

The square root of 20977571 is about 4580.1278366439. The cubic root of 20977571 is about 275.7941605688.

The spelling of 20977571 in words is "twenty million, nine hundred seventy-seven thousand, five hundred seventy-one".