642739929 has 16 divisors (see below), whose sum is σ = 925542912. Its totient is φ = 394403328.

The previous prime is 642739921. The next prime is 642739943. The reversal of 642739929 is 929937246.

It is not a de Polignac number, because 642739929 - 2³ = 642739921 is a prime.

It is a super-2 number, since 2×642739929² = 826229232661850082, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (642739921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9577 + ... + 37110.

It is an arithmetic number, because the mean of its divisors is an integer number (57846432).

Almost surely, 2^642739929 is an apocalyptic number.

It is an amenable number.

642739929 is a deficient number, since it is larger than the sum of its proper divisors (282802983).

642739929 is a wasteful number, since it uses less digits than its factorization.

642739929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47056.

The product of its digits is 1469664, while the sum is 51.

The square root of 642739929 is about 25352.3160480458. The cubic root of 642739929 is about 863.0019164736.

The spelling of 642739929 in words is "six hundred forty-two million, seven hundred thirty-nine thousand, nine hundred twenty-nine".