642516026 has 16 divisors (see below), whose sum is σ = 997062696. Its totient is φ = 310288896.

The previous prime is 642516011. The next prime is 642516041. The reversal of 642516026 is 620615246.

It is an interprime number because it is at equal distance from previous prime (642516011) and next prime (642516041).

It can be written as a sum of positive squares in 4 ways, for example, as 526932025 + 115584001 = 22955^2 + 10751^2 .

It is a junction number, because it is equal to n+sod(n) for n = 642515983 and 642516001.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21551 + ... + 41826.

Almost surely, 2^642516026 is an apocalyptic number.

642516026 is a deficient number, since it is larger than the sum of its proper divisors (354546670).

642516026 is a wasteful number, since it uses less digits than its factorization.

642516026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63553.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 642516026 is about 25347.8998341085. The cubic root of 642516026 is about 862.9016938946.

The spelling of 642516026 in words is "six hundred forty-two million, five hundred sixteen thousand, twenty-six".