642913690 has 8 divisors (see below), whose sum is σ = 1157244660. Its totient is φ = 257165472.

The previous prime is 642913657. The next prime is 642913699. The reversal of 642913690 is 96319246.

It can be written as a sum of positive squares in 2 ways, for example, as 592971201 + 49942489 = 24351^2 + 7067^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×642913690² = 826676025578832200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (642913699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32145675 + ... + 32145694.

Almost surely, 2^642913690 is an apocalyptic number.

642913690 is a deficient number, since it is larger than the sum of its proper divisors (514330970).

642913690 is a wasteful number, since it uses less digits than its factorization.

642913690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64291376.

The product of its (nonzero) digits is 69984, while the sum is 40.

The square root of 642913690 is about 25355.7427420299. The cubic root of 642913690 is about 863.0796786488.

The spelling of 642913690 in words is "six hundred forty-two million, nine hundred thirteen thousand, six hundred ninety".