31555242440 has 32 divisors (see below), whose sum is σ = 71013215160. Its totient is φ = 12619622400.

The previous prime is 31555242437. The next prime is 31555242473. The reversal of 31555242440 is 4424255513.

It can be written as a sum of positive squares in 4 ways, for example, as 27518164996 + 4037077444 = 165886^2 + 63538^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 31555242440.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136550 + ... + 285930.

Almost surely, 2^31555242440 is an apocalyptic number.

It is an amenable number.

31555242440 is an abundant number, since it is smaller than the sum of its proper divisors (39457972720).

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

31555242440 is a wasteful number, since it uses less digits than its factorization.

31555242440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154673 (or 154669 counting only the distinct ones).

The product of its (nonzero) digits is 96000, while the sum is 35.

Adding to 31555242440 its reverse (4424255513), we get a palindrome (35979497953).

The spelling of 31555242440 in words is "thirty-one billion, five hundred fifty-five million, two hundred forty-two thousand, four hundred forty".