405720642 has 16 divisors (see below), whose sum is σ = 854148960. Its totient is φ = 128122272.

The previous prime is 405720629. The next prime is 405720649. The reversal of 405720642 is 246027504.

It is not an unprimeable number, because it can be changed into a prime (405720649) 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 7 ways as a sum of consecutive naturals, for example, 1779363 + ... + 1779590.

It is an arithmetic number, because the mean of its divisors is an integer number (53384310).

Almost surely, 2^405720642 is an apocalyptic number.

405720642 is an abundant number, since it is smaller than the sum of its proper divisors (448428318).

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

405720642 is a wasteful number, since it uses less digits than its factorization.

405720642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3558977.

The product of its (nonzero) digits is 13440, while the sum is 30.

The square root of 405720642 is about 20142.5083343659. The cubic root of 405720642 is about 740.3021909200.

The spelling of 405720642 in words is "four hundred five million, seven hundred twenty thousand, six hundred forty-two".