20401585 has 8 divisors (see below), whose sum is σ = 24699240. Its totient is φ = 16176384.

The previous prime is 20401571. The next prime is 20401603. The reversal of 20401585 is 58510402.

It can be written as a sum of positive squares in 4 ways, for example, as 2702736 + 17698849 = 1644^2 + 4207^2 .

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 20401585 - 2⁵ = 20401553 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17490 + ... + 18619.

It is an arithmetic number, because the mean of its divisors is an integer number (3087405).

Almost surely, 2^20401585 is an apocalyptic number.

It is an amenable number.

20401585 is a deficient number, since it is larger than the sum of its proper divisors (4297655).

20401585 is a wasteful number, since it uses less digits than its factorization.

20401585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36227.

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 20401585 is about 4516.8113752956. The cubic root of 20401585 is about 273.2465179705.

Adding to 20401585 its reverse (58510402), we get a palindrome (78911987).

The spelling of 20401585 in words is "twenty million, four hundred one thousand, five hundred eighty-five".