20621677 has 2 divisors, whose sum is σ = 20621678. Its totient is φ = 20621676.

The previous prime is 20621609. The next prime is 20621683. The reversal of 20621677 is 77612602.

20621677 is nontrivially palindromic in base 5.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19527561 + 1094116 = 4419^2 + 1046^2 .

It is a cyclic number.

It is not a de Polignac number, because 20621677 - 2¹¹ = 20619629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20621077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10310838 + 10310839.

It is an arithmetic number, because the mean of its divisors is an integer number (10310839).

Almost surely, 2^20621677 is an apocalyptic number.

It is an amenable number.

20621677 is a deficient number, since it is larger than the sum of its proper divisors (1).

20621677 is an equidigital number, since it uses as much as digits as its factorization.

20621677 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 20621677 is about 4541.1096661499. The cubic root of 20621677 is about 274.2255987399.

The spelling of 20621677 in words is "twenty million, six hundred twenty-one thousand, six hundred seventy-seven".