31551240042 has 144 divisors (see below), whose sum is σ = 82658040192. Its totient is φ = 8993799360.

The previous prime is 31551240037. The next prime is 31551240059. The reversal of 31551240042 is 24004215513.

31551240042 is a `hidden beast` number, since 31 + 551 + 2 + 40 + 0 + 42 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 31551239988 and 31551240015.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 12405823 + ... + 12408365.

It is an arithmetic number, because the mean of its divisors is an integer number (574014168).

Almost surely, 2^31551240042 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31551240042, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41329020096).

31551240042 is an abundant number, since it is smaller than the sum of its proper divisors (51106800150).

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

31551240042 is a wasteful number, since it uses less digits than its factorization.

31551240042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3095 (or 3076 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

Adding to 31551240042 its reverse (24004215513), we get a palindrome (55555455555).

The spelling of 31551240042 in words is "thirty-one billion, five hundred fifty-one million, two hundred forty thousand, forty-two".