20215140 has 96 divisors (see below), whose sum is σ = 62536320. Its totient is φ = 4838400.

The previous prime is 20215133. The next prime is 20215147. The reversal of 20215140 is 4151202.

It is an interprime number because it is at equal distance from previous prime (20215133) and next prime (20215147).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20215147) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 71800 + ... + 72080.

It is an arithmetic number, because the mean of its divisors is an integer number (651420).

Almost surely, 2^20215140 is an apocalyptic number.

20215140 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 20215140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31268160).

20215140 is an abundant number, since it is smaller than the sum of its proper divisors (42321180).

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

20215140 is a wasteful number, since it uses less digits than its factorization.

20215140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413 (or 411 counting only the distinct ones).

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

The square root of 20215140 is about 4496.1249982624. The cubic root of 20215140 is about 272.4115921158.

Adding to 20215140 its reverse (4151202), we get a palindrome (24366342).

The spelling of 20215140 in words is "twenty million, two hundred fifteen thousand, one hundred forty".