20091240 has 224 divisors, whose sum is σ = 74367720. Its totient is φ = 4852224.

The previous prime is 20091233. The next prime is 20091251. The reversal of 20091240 is 4219002.

It can be written as a sum of positive squares in 4 ways, for example, as 14699556 + 5391684 = 3834^2 + 2322^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 379054 + ... + 379106.

Almost surely, 2^20091240 is an apocalyptic number.

20091240 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 20091240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37183860).

20091240 is an abundant number, since it is smaller than the sum of its proper divisors (54276480).

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

20091240 is a wasteful number, since it uses less digits than its factorization.

20091240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 76 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 20091240 is about 4482.3252894006. The cubic root of 20091240 is about 271.8539079951.

It can be divided in two parts, 2009 and 1240, that added together give a square (3249 = 57²).

The spelling of 20091240 in words is "twenty million, ninety-one thousand, two hundred forty".