397872540 has 288 divisors, whose sum is σ = 1415856960. Its totient is φ = 92192256.

The previous prime is 397872533. The next prime is 397872583. The reversal of 397872540 is 45278793.

397872540 is a `hidden beast` number, since 39 + 7 + 8 + 72 + 540 = 666.

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 pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2534142 + ... + 2534298.

It is an arithmetic number, because the mean of its divisors is an integer number (4916170).

Almost surely, 2^397872540 is an apocalyptic number.

397872540 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 397872540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (707928480).

397872540 is an abundant number, since it is smaller than the sum of its proper divisors (1017984420).

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

397872540 is a wasteful number, since it uses less digits than its factorization.

397872540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226 (or 199 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 45.

The square root of 397872540 is about 19946.7425912102. The cubic root of 397872540 is about 735.4977053849.

The spelling of 397872540 in words is "three hundred ninety-seven million, eight hundred seventy-two thousand, five hundred forty".