240721920 has 168 divisors, whose sum is σ = 835729596. Its totient is φ = 64094208.

The previous prime is 240721909. The next prime is 240721931. The reversal of 240721920 is 29127042.

It is an interprime number because it is at equal distance from previous prime (240721909) and next prime (240721931).

It can be written as a sum of positive squares in 2 ways, for example, as 230068224 + 10653696 = 15168^2 + 3264^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 368314 + ... + 368966.

Almost surely, 2^240721920 is an apocalyptic number.

240721920 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 240721920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (417864798).

240721920 is an abundant number, since it is smaller than the sum of its proper divisors (595007676).

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

240721920 is an equidigital number, since it uses as much as digits as its factorization.

240721920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 690 (or 663 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 240721920 is about 15515.2157574428. The cubic root of 240721920 is about 622.0689811593.

Adding to 240721920 its reverse (29127042), we get a palindrome (269848962).

The spelling of 240721920 in words is "two hundred forty million, seven hundred twenty-one thousand, nine hundred twenty".