145531397820 has 384 divisors, whose sum is σ = 456162803712. Its totient is φ = 34501017600.

The previous prime is 145531397819. The next prime is 145531397899. The reversal of 145531397820 is 28793135541.

145531397820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 145531397820.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 379977349 + ... + 379977731.

It is an arithmetic number, because the mean of its divisors is an integer number (1187923968).

Almost surely, 2^145531397820 is an apocalyptic number.

145531397820 is a gapful number since it is divisible by the number (10) 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 145531397820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (228081401856).

145531397820 is an abundant number, since it is smaller than the sum of its proper divisors (310631405892).

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

145531397820 is a wasteful number, since it uses less digits than its factorization.

145531397820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701 (or 699 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 48.

The spelling of 145531397820 in words is "one hundred forty-five billion, five hundred thirty-one million, three hundred ninety-seven thousand, eight hundred twenty".