20051687 has 6 divisors (see below), whose sum is σ = 21300888. Its totient is φ = 18871904.

The previous prime is 20051683. The next prime is 20051711. The reversal of 20051687 is 78615002.

It is not a de Polignac number, because 20051687 - 2² = 20051683 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 (20051683) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 34403 + ... + 34980.

It is an arithmetic number, because the mean of its divisors is an integer number (3550148).

Almost surely, 2^20051687 is an apocalyptic number.

20051687 is a deficient number, since it is larger than the sum of its proper divisors (1249201).

20051687 is an equidigital number, since it uses as much as digits as its factorization.

20051687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69417 (or 69400 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 20051687 is about 4477.9110084949. The cubic root of 20051687 is about 271.6753940179.

Adding to 20051687 its reverse (78615002), we get a palindrome (98666689).

The spelling of 20051687 in words is "twenty million, fifty-one thousand, six hundred eighty-seven".