661258929 has 4 divisors (see below), whose sum is σ = 881678576. Its totient is φ = 440839284.

The previous prime is 661258907. The next prime is 661258943. The reversal of 661258929 is 929852166.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 661258929 - 2²¹ = 659161777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661258529) 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, 110209819 + ... + 110209824.

It is an arithmetic number, because the mean of its divisors is an integer number (220419644).

Almost surely, 2^661258929 is an apocalyptic number.

It is an amenable number.

661258929 is a deficient number, since it is larger than the sum of its proper divisors (220419647).

661258929 is a wasteful number, since it uses less digits than its factorization.

661258929 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220419646.

The product of its digits is 466560, while the sum is 48.

The square root of 661258929 is about 25714.9553567569. The cubic root of 661258929 is about 871.2120021413.

The spelling of 661258929 in words is "six hundred sixty-one million, two hundred fifty-eight thousand, nine hundred twenty-nine".