642754021 has 48 divisors (see below), whose sum is σ = 884822400. Its totient is φ = 460639872.

The previous prime is 642754009. The next prime is 642754051. The reversal of 642754021 is 120457246.

It is not a de Polignac number, because 642754021 - 2⁷ = 642753893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642754051) 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 47 ways as a sum of consecutive naturals, for example, 277215 + ... + 279523.

It is an arithmetic number, because the mean of its divisors is an integer number (18433800).

Almost surely, 2^642754021 is an apocalyptic number.

It is an amenable number.

642754021 is a deficient number, since it is larger than the sum of its proper divisors (242068379).

642754021 is a wasteful number, since it uses less digits than its factorization.

642754021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2378 (or 2371 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 31.

The square root of 642754021 is about 25352.5939698485. The cubic root of 642754021 is about 863.0082235006.

The spelling of 642754021 in words is "six hundred forty-two million, seven hundred fifty-four thousand, twenty-one".