642440521402 has 32 divisors (see below), whose sum is σ = 1022193768960. Its totient is φ = 301778146560.

The previous prime is 642440521381. The next prime is 642440521417. The reversal of 642440521402 is 204125044246.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53366128 + ... + 53378164.

It is an arithmetic number, because the mean of its divisors is an integer number (31943555280).

Almost surely, 2^642440521402 is an apocalyptic number.

642440521402 is a deficient number, since it is larger than the sum of its proper divisors (379753247558).

642440521402 is a wasteful number, since it uses less digits than its factorization.

642440521402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14766.

The product of its (nonzero) digits is 61440, while the sum is 34.

Adding to 642440521402 its reverse (204125044246), we get a palindrome (846565565648).

The spelling of 642440521402 in words is "six hundred forty-two billion, four hundred forty million, five hundred twenty-one thousand, four hundred two".