397765728 has 252 divisors, whose sum is σ = 1268382780. Its totient is φ = 122674176.

The previous prime is 397765673. The next prime is 397765733. The reversal of 397765728 is 827567793.

It is a Harshad number since it is a multiple of its sum of digits (54).

Its product of digits (4445280) is a multiple of the sum of its prime divisors (81).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 6741763 + ... + 6741821.

It is an arithmetic number, because the mean of its divisors is an integer number (5033265).

Almost surely, 2^397765728 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 397765728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (634191390).

397765728 is an abundant number, since it is smaller than the sum of its proper divisors (870617052).

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

397765728 is an equidigital number, since it uses as much as digits as its factorization.

397765728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121 (or 81 counting only the distinct ones).

The product of its digits is 4445280, while the sum is 54.

The square root of 397765728 is about 19944.0649818436. The cubic root of 397765728 is about 735.4318827876.

The spelling of 397765728 in words is "three hundred ninety-seven million, seven hundred sixty-five thousand, seven hundred twenty-eight".