20649877 has 4 divisors (see below), whose sum is σ = 20678560. Its totient is φ = 20621196.

The previous prime is 20649859. The next prime is 20649887. The reversal of 20649877 is 77894602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20649877 - 2²³ = 12261269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20649817) 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, 13233 + ... + 14710.

It is an arithmetic number, because the mean of its divisors is an integer number (5169640).

Almost surely, 2^20649877 is an apocalyptic number.

It is an amenable number.

20649877 is a deficient number, since it is larger than the sum of its proper divisors (28683).

20649877 is an equidigital number, since it uses as much as digits as its factorization.

20649877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28682.

The product of its (nonzero) digits is 169344, while the sum is 43.

The square root of 20649877 is about 4544.2135733260. The cubic root of 20649877 is about 274.3505423376.

The spelling of 20649877 in words is "twenty million, six hundred forty-nine thousand, eight hundred seventy-seven".