20420387 has 8 divisors (see below), whose sum is σ = 22194480. Its totient is φ = 18675360.

The previous prime is 20420377. The next prime is 20420443. The reversal of 20420387 is 78302402.

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 20420387 - 2⁴ = 20420371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20420347) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5789 + ... + 8622.

It is an arithmetic number, because the mean of its divisors is an integer number (2774310).

Almost surely, 2^20420387 is an apocalyptic number.

20420387 is a deficient number, since it is larger than the sum of its proper divisors (1774093).

20420387 is a wasteful number, since it uses less digits than its factorization.

20420387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14533.

The product of its (nonzero) digits is 2688, while the sum is 26.

The square root of 20420387 is about 4518.8922315098. The cubic root of 20420387 is about 273.3304330778.

Adding to 20420387 its reverse (78302402), we get a palindrome (98722789).

The spelling of 20420387 in words is "twenty million, four hundred twenty thousand, three hundred eighty-seven".