402446640 has 80 divisors (see below), whose sum is σ = 1301845248. Its totient is φ = 102651648.

The previous prime is 402446633. The next prime is 402446641. The reversal of 402446640 is 46644204.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 402446598 and 402446607.

It is not an unprimeable number, because it can be changed into a prime (402446641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30934 + ... + 41973.

Almost surely, 2^402446640 is an apocalyptic number.

402446640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

402446640 is an abundant number, since it is smaller than the sum of its proper divisors (899398608).

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

402446640 is a wasteful number, since it uses less digits than its factorization.

402446640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72946 (or 72940 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 30.

The square root of 402446640 is about 20061.0727529711. The cubic root of 402446640 is about 738.3054970111.

The spelling of 402446640 in words is "four hundred two million, four hundred forty-six thousand, six hundred forty".