421780216578 has 384 divisors, whose sum is σ = 1098086989824. Its totient is φ = 107296358400.

The previous prime is 421780216549. The next prime is 421780216607. The reversal of 421780216578 is 875612087124.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (421780216549) and next prime (421780216607).

It is a self number, because there is not a number n which added to its sum of digits gives 421780216578.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 658003138 + ... + 658003778.

It is an arithmetic number, because the mean of its divisors is an integer number (2859601536).

Almost surely, 2^421780216578 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 421780216578, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (549043494912).

421780216578 is an abundant number, since it is smaller than the sum of its proper divisors (676306773246).

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

421780216578 is a wasteful number, since it uses less digits than its factorization.

421780216578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 830 (or 823 counting only the distinct ones).

The product of its (nonzero) digits is 1505280, while the sum is 51.

The spelling of 421780216578 in words is "four hundred twenty-one billion, seven hundred eighty million, two hundred sixteen thousand, five hundred seventy-eight".