1397636478 has 32 divisors (see below), whose sum is σ = 3549553920. Its totient is φ = 399324600.

The previous prime is 1397636467. The next prime is 1397636489. The reversal of 1397636478 is 8746367931.

1397636478 is a `hidden beast` number, since 139 + 7 + 6 + 36 + 478 = 666.

It is an interprime number because it is at equal distance from previous prime (1397636467) and next prime (1397636489).

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

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 15 ways as a sum of consecutive naturals, for example, 1848348 + ... + 1849103.

It is an arithmetic number, because the mean of its divisors is an integer number (110923560).

Almost surely, 2^1397636478 is an apocalyptic number.

1397636478 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1397636478 is an abundant number, since it is smaller than the sum of its proper divisors (2151917442).

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

1397636478 is a wasteful number, since it uses less digits than its factorization.

1397636478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3697469 (or 3697463 counting only the distinct ones).

The product of its digits is 4572288, while the sum is 54.

The square root of 1397636478 is about 37384.9766350067. The cubic root of 1397636478 is about 1118.0590527380.

The spelling of 1397636478 in words is "one billion, three hundred ninety-seven million, six hundred thirty-six thousand, four hundred seventy-eight".