31898240640 has 448 divisors, whose sum is σ = 130679429760. Its totient is φ = 7290279936.

The previous prime is 31898240603. The next prime is 31898240651. The reversal of 31898240640 is 4604289813.

It is a happy number.

31898240640 is a `hidden beast` number, since 318 + 98 + 240 + 6 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 3261037 + ... + 3270803.

Almost surely, 2^31898240640 is an apocalyptic number.

31898240640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31898240640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65339714880).

31898240640 is an abundant number, since it is smaller than the sum of its proper divisors (98781189120).

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

31898240640 is an frugal number, since it uses more digits than its factorization.

31898240640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9811 (or 9784 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The spelling of 31898240640 in words is "thirty-one billion, eight hundred ninety-eight million, two hundred forty thousand, six hundred forty".