20387977 has 8 divisors (see below), whose sum is σ = 20956320. Its totient is φ = 19824000.

The previous prime is 20387953. The next prime is 20387993. The reversal of 20387977 is 77978302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20387977 - 2⁷ = 20387849 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20384977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9849 + ... + 11737.

It is an arithmetic number, because the mean of its divisors is an integer number (2619540).

Almost surely, 2^20387977 is an apocalyptic number.

It is an amenable number.

20387977 is a deficient number, since it is larger than the sum of its proper divisors (568343).

20387977 is a wasteful number, since it uses less digits than its factorization.

20387977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2183.

The product of its (nonzero) digits is 148176, while the sum is 43.

The square root of 20387977 is about 4515.3047516198. The cubic root of 20387977 is about 273.1857520114.

The spelling of 20387977 in words is "twenty million, three hundred eighty-seven thousand, nine hundred seventy-seven".