240721990 has 16 divisors (see below), whose sum is σ = 437768352. Its totient is φ = 95295744.

The previous prime is 240721981. The next prime is 240721997. The reversal of 240721990 is 99127042.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (240721997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 123114 + ... + 125053.

It is an arithmetic number, because the mean of its divisors is an integer number (27360522).

Almost surely, 2^240721990 is an apocalyptic number.

240721990 is a deficient number, since it is larger than the sum of its proper divisors (197046362).

240721990 is a wasteful number, since it uses less digits than its factorization.

240721990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248271.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 240721990 is about 15515.2180132926. The cubic root of 240721990 is about 622.0690414568.

It can be divided in two parts, 24072 and 1990, that added together give a palindrome (26062).

The spelling of 240721990 in words is "two hundred forty million, seven hundred twenty-one thousand, nine hundred ninety".