397787540 has 12 divisors (see below), whose sum is σ = 835353876. Its totient is φ = 159115008.

The previous prime is 397787531. The next prime is 397787549. The reversal of 397787540 is 45787793.

It is an interprime number because it is at equal distance from previous prime (397787531) and next prime (397787549).

It can be written as a sum of positive squares in 2 ways, for example, as 71334916 + 326452624 = 8446^2 + 18068^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397787549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9944669 + ... + 9944708.

It is an arithmetic number, because the mean of its divisors is an integer number (69612823).

Almost surely, 2^397787540 is an apocalyptic number.

It is an amenable number.

397787540 is an abundant number, since it is smaller than the sum of its proper divisors (437566336).

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

397787540 is a wasteful number, since it uses less digits than its factorization.

397787540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19889386 (or 19889384 counting only the distinct ones).

The product of its (nonzero) digits is 1481760, while the sum is 50.

The square root of 397787540 is about 19944.6118036927. The cubic root of 397787540 is about 735.4453253292.

The spelling of 397787540 in words is "three hundred ninety-seven million, seven hundred eighty-seven thousand, five hundred forty".