642449394 has 80 divisors (see below), whose sum is σ = 1564442880. Its totient is φ = 196305120.

The previous prime is 642449359. The next prime is 642449417. The reversal of 642449394 is 493944246.

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 39 ways as a sum of consecutive naturals, for example, 92052 + ... + 98784.

It is an arithmetic number, because the mean of its divisors is an integer number (19555536).

Almost surely, 2^642449394 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642449394, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (782221440).

642449394 is an abundant number, since it is smaller than the sum of its proper divisors (921993486).

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

642449394 is a wasteful number, since it uses less digits than its factorization.

642449394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6797 (or 6788 counting only the distinct ones).

The product of its digits is 746496, while the sum is 45.

The square root of 642449394 is about 25346.5854505099. The cubic root of 642449394 is about 862.8718638458.

The spelling of 642449394 in words is "six hundred forty-two million, four hundred forty-nine thousand, three hundred ninety-four".