20693977 has 4 divisors (see below), whose sum is σ = 20883940. Its totient is φ = 20504016.

The previous prime is 20693941. The next prime is 20693993. The reversal of 20693977 is 77939602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14523721 + 6170256 = 3811^2 + 2484^2 .

It is a cyclic number.

It is not a de Polignac number, because 20693977 - 2¹¹ = 20691929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20693917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94818 + ... + 95035.

It is an arithmetic number, because the mean of its divisors is an integer number (5220985).

Almost surely, 2^20693977 is an apocalyptic number.

It is an amenable number.

20693977 is a deficient number, since it is larger than the sum of its proper divisors (189963).

20693977 is a wasteful number, since it uses less digits than its factorization.

20693977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189962.

The product of its (nonzero) digits is 142884, while the sum is 43.

The square root of 20693977 is about 4549.0633101772. The cubic root of 20693977 is about 274.5457050227.

The spelling of 20693977 in words is "twenty million, six hundred ninety-three thousand, nine hundred seventy-seven".