642929409 has 12 divisors (see below), whose sum is σ = 983304036. Its totient is φ = 403406592.

The previous prime is 642929407. The next prime is 642929411. The reversal of 642929409 is 904929246.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (642929407) and next prime (642929411).

It can be written as a sum of positive squares in 2 ways, for example, as 425514384 + 217415025 = 20628^2 + 14745^2 .

It is not a de Polignac number, because 642929409 - 2¹ = 642929407 is a prime.

It is not an unprimeable number, because it can be changed into a prime (642929401) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 2100924 + ... + 2101229.

It is an arithmetic number, because the mean of its divisors is an integer number (81942003).

Almost surely, 2^642929409 is an apocalyptic number.

It is an amenable number.

642929409 is a deficient number, since it is larger than the sum of its proper divisors (340374627).

642929409 is a wasteful number, since it uses less digits than its factorization.

642929409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4202176 (or 4202173 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The square root of 642929409 is about 25356.0527093631. The cubic root of 642929409 is about 863.0867125836.

The spelling of 642929409 in words is "six hundred forty-two million, nine hundred twenty-nine thousand, four hundred nine".