20766861 has 40 divisors (see below), whose sum is σ = 33035904. Its totient is φ = 12972960.

The previous prime is 20766859. The next prime is 20766887. The reversal of 20766861 is 16866702.

It is a happy number.

It is not a de Polignac number, because 20766861 - 2¹ = 20766859 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20766661) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 132195 + ... + 132351.

Almost surely, 2^20766861 is an apocalyptic number.

It is an amenable number.

20766861 is a deficient number, since it is larger than the sum of its proper divisors (12269043).

20766861 is a wasteful number, since it uses less digits than its factorization.

20766861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263 (or 254 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 20766861 is about 4557.0671489457. The cubic root of 20766861 is about 274.8676431943.

The spelling of 20766861 in words is "twenty million, seven hundred sixty-six thousand, eight hundred sixty-one".