6402477978 has 96 divisors (see below), whose sum is σ = 15589968576. Its totient is φ = 1957592448.

The previous prime is 6402477953. The next prime is 6402477997. The reversal of 6402477978 is 8797742046.

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

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1026726 + ... + 1032942.

It is an arithmetic number, because the mean of its divisors is an integer number (162395506).

Almost surely, 2^6402477978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6402477978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7794984288).

6402477978 is an abundant number, since it is smaller than the sum of its proper divisors (9187490598).

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

6402477978 is a wasteful number, since it uses less digits than its factorization.

6402477978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6410 (or 6398 counting only the distinct ones).

The product of its (nonzero) digits is 4741632, while the sum is 54.

The square root of 6402477978 is about 80015.4858636752. The cubic root of 6402477978 is about 1856.8751224222.

The spelling of 6402477978 in words is "six billion, four hundred two million, four hundred seventy-seven thousand, nine hundred seventy-eight".