31421089728 has 784 divisors, whose sum is σ = 115135395840. Its totient is φ = 8309993472.

The previous prime is 31421089703. The next prime is 31421089729. The reversal of 31421089728 is 82798012413.

It is a happy number.

It is a super-2 number, since 2×31421089728² (a number of 22 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31421089729) by changing a digit.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 353045908 + ... + 353045996.

Almost surely, 2^31421089728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31421089728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (57567697920).

31421089728 is an abundant number, since it is smaller than the sum of its proper divisors (83714306112).

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

31421089728 is an equidigital number, since it uses as much as digits as its factorization.

31421089728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The spelling of 31421089728 in words is "thirty-one billion, four hundred twenty-one million, eighty-nine thousand, seven hundred twenty-eight".