20867261 has 2 divisors, whose sum is σ = 20867262. Its totient is φ = 20867260.

The previous prime is 20867257. The next prime is 20867281. The reversal of 20867261 is 16276802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18541636 + 2325625 = 4306^2 + 1525^2 .

It is a cyclic number.

It is not a de Polignac number, because 20867261 - 2² = 20867257 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20867221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10433630 + 10433631.

It is an arithmetic number, because the mean of its divisors is an integer number (10433631).

Almost surely, 2^20867261 is an apocalyptic number.

It is an amenable number.

20867261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20867261 is an equidigital number, since it uses as much as digits as its factorization.

20867261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 20867261 is about 4568.0697236360. The cubic root of 20867261 is about 275.3098919801.

The spelling of 20867261 in words is "twenty million, eight hundred sixty-seven thousand, two hundred sixty-one".