240405631 has 4 divisors (see below), whose sum is σ = 241132264. Its totient is φ = 239679000.

The previous prime is 240405629. The next prime is 240405667. The reversal of 240405631 is 136504042.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 136504042 = 2 ⋅68252021.

It is a cyclic number.

It is not a de Polignac number, because 240405631 - 2¹ = 240405629 is a prime.

It is a super-2 number, since 2×240405631² = 115589734833016322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 240405596 and 240405605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (240400631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 362820 + ... + 363481.

It is an arithmetic number, because the mean of its divisors is an integer number (60283066).

Almost surely, 2^240405631 is an apocalyptic number.

240405631 is a deficient number, since it is larger than the sum of its proper divisors (726633).

240405631 is an equidigital number, since it uses as much as digits as its factorization.

240405631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 726632.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 240405631 is about 15505.0195420709. The cubic root of 240405631 is about 621.7964124188.

Adding to 240405631 its reverse (136504042), we get a palindrome (376909673).

The spelling of 240405631 in words is "two hundred forty million, four hundred five thousand, six hundred thirty-one".