20151071 has 4 divisors (see below), whose sum is σ = 20358912. Its totient is φ = 19943232.

The previous prime is 20151067. The next prime is 20151091. The reversal of 20151071 is 17015102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20151071 - 2² = 20151067 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 (20151011) 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, 103775 + ... + 103968.

It is an arithmetic number, because the mean of its divisors is an integer number (5089728).

Almost surely, 2^20151071 is an apocalyptic number.

20151071 is a deficient number, since it is larger than the sum of its proper divisors (207841).

20151071 is an equidigital number, since it uses as much as digits as its factorization.

20151071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207840.

The product of its (nonzero) digits is 70, while the sum is 17.

The square root of 20151071 is about 4488.9944308275. The cubic root of 20151071 is about 272.1234976605.

Adding to 20151071 its reverse (17015102), we get a palindrome (37166173).

The spelling of 20151071 in words is "twenty million, one hundred fifty-one thousand, seventy-one".