642220040 has 64 divisors (see below), whose sum is σ = 1801560960. Its totient is φ = 200171520.

The previous prime is 642220039. The next prime is 642220057. The reversal of 642220040 is 40022246.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 642219994 and 642220021.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 101177 + ... + 107336.

It is an arithmetic number, because the mean of its divisors is an integer number (28149390).

Almost surely, 2^642220040 is an apocalyptic number.

It is an amenable number.

642220040 is an abundant number, since it is smaller than the sum of its proper divisors (1159340920).

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

642220040 is a wasteful number, since it uses less digits than its factorization.

642220040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208542 (or 208538 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 642220040 is about 25342.0606896914. The cubic root of 642220040 is about 862.7691700666.

Adding to 642220040 its reverse (40022246), we get a palindrome (682242286).

It can be divided in two parts, 6422 and 20040, that added together give a palindrome (26462).

The spelling of 642220040 in words is "six hundred forty-two million, two hundred twenty thousand, forty".