20151000 has 96 divisors (see below), whose sum is σ = 68140800. Its totient is φ = 5371200.

The previous prime is 20150983. The next prime is 20151011. The reversal of 20151000 is 15102.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7881 + ... + 10119.

It is an arithmetic number, because the mean of its divisors is an integer number (709800).

Almost surely, 2^20151000 is an apocalyptic number.

20151000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20151000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34070400).

20151000 is an abundant number, since it is smaller than the sum of its proper divisors (47989800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20151000 is a wasteful number, since it uses less digits than its factorization.

20151000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2266 (or 2249 counting only the distinct ones).

The product of its (nonzero) digits is 10, while the sum is 9.

The square root of 20151000 is about 4488.9865225906. The cubic root of 20151000 is about 272.1231780615.

Adding to 20151000 its reverse (15102), we get a palindrome (20166102).

The spelling of 20151000 in words is "twenty million, one hundred fifty-one thousand".