20015501 has 4 divisors (see below), whose sum is σ = 21835104. Its totient is φ = 18195900.

The previous prime is 20015461. The next prime is 20015507. The reversal of 20015501 is 10551002.

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 20015501 - 2¹⁴ = 19999117 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 (20015507) 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, 909785 + ... + 909806.

It is an arithmetic number, because the mean of its divisors is an integer number (5458776).

Almost surely, 2^20015501 is an apocalyptic number.

It is an amenable number.

20015501 is a deficient number, since it is larger than the sum of its proper divisors (1819603).

20015501 is a wasteful number, since it uses less digits than its factorization.

20015501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1819602.

The product of its (nonzero) digits is 50, while the sum is 14.

The square root of 20015501 is about 4473.8686838127. The cubic root of 20015501 is about 271.5118705291.

Adding to 20015501 its reverse (10551002), we get a palindrome (30566503).

The spelling of 20015501 in words is "twenty million, fifteen thousand, five hundred one".