421569978 has 48 divisors (see below), whose sum is σ = 912622464. Its totient is φ = 129374080.

The previous prime is 421569977. The next prime is 421569983. The reversal of 421569978 is 879965124.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a self number, because there is not a number n which added to its sum of digits gives 421569978.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421569977) 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 23 ways as a sum of consecutive naturals, for example, 224383 + ... + 226253.

It is an arithmetic number, because the mean of its divisors is an integer number (19012968).

Almost surely, 2^421569978 is an apocalyptic number.

421569978 is an abundant number, since it is smaller than the sum of its proper divisors (491052486).

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

421569978 is a wasteful number, since it uses less digits than its factorization.

421569978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1987 (or 1940 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 51.

The square root of 421569978 is about 20532.1693447137. The cubic root of 421569978 is about 749.8192026421.

The spelling of 421569978 in words is "four hundred twenty-one million, five hundred sixty-nine thousand, nine hundred seventy-eight".