31551120020 has 24 divisors (see below), whose sum is σ = 75722688384. Its totient is φ = 10817526816.

The previous prime is 31551120019. The next prime is 31551120049. The reversal of 31551120020 is 2002115513.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 31551119974 and 31551120001.

It is a congruent number.

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, 112682432 + ... + 112682711.

It is an arithmetic number, because the mean of its divisors is an integer number (3155112016).

Almost surely, 2^31551120020 is an apocalyptic number.

It is an amenable number.

31551120020 is an abundant number, since it is smaller than the sum of its proper divisors (44171568364).

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

31551120020 is a wasteful number, since it uses less digits than its factorization.

31551120020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225365159 (or 225365157 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 20.

Adding to 31551120020 its reverse (2002115513), we get a palindrome (33553235533).

The spelling of 31551120020 in words is "thirty-one billion, five hundred fifty-one million, one hundred twenty thousand, twenty".