20421150 has 48 divisors (see below), whose sum is σ = 51150000. Its totient is φ = 5391360.

The previous prime is 20421103. The next prime is 20421179. The reversal of 20421150 is 5112402.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a Curzon number.

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, 15726 + ... + 16974.

It is an arithmetic number, because the mean of its divisors is an integer number (1065625).

Almost surely, 2^20421150 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20421150, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25575000).

20421150 is an abundant number, since it is smaller than the sum of its proper divisors (30728850).

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

20421150 is a wasteful number, since it uses less digits than its factorization.

20421150 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1373 (or 1368 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 20421150 is about 4518.9766540667. The cubic root of 20421150 is about 273.3338373313. Note that the first 3 decimals are identical.

Adding to 20421150 its reverse (5112402), we get a palindrome (25533552).

The spelling of 20421150 in words is "twenty million, four hundred twenty-one thousand, one hundred fifty".