1401597978 has 64 divisors (see below), whose sum is σ = 3165696000. Its totient is φ = 409852800.

The previous prime is 1401597971. The next prime is 1401597979. The reversal of 1401597978 is 8797951041.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1401597978.

It is not an unprimeable number, because it can be changed into a prime (1401597971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 934273 + ... + 935771.

It is an arithmetic number, because the mean of its divisors is an integer number (49464000).

Almost surely, 2^1401597978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1401597978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1582848000).

1401597978 is an abundant number, since it is smaller than the sum of its proper divisors (1764098022).

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

1401597978 is a wasteful number, since it uses less digits than its factorization.

1401597978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2003.

The product of its (nonzero) digits is 635040, while the sum is 51.

The square root of 1401597978 is about 37437.9216570578. The cubic root of 1401597978 is about 1119.1144088919.

The spelling of 1401597978 in words is "one billion, four hundred one million, five hundred ninety-seven thousand, nine hundred seventy-eight".