647729506 has 8 divisors (see below), whose sum is σ = 972591660. Its totient is φ = 323532288.

The previous prime is 647729501. The next prime is 647729539. The reversal of 647729506 is 605927746.

It can be written as a sum of positive squares in 2 ways, for example, as 508277025 + 139452481 = 22545^2 + 11809^2 .

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

It is not an unprimeable number, because it can be changed into a prime (647729501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 163791 + ... + 167698.

Almost surely, 2^647729506 is an apocalyptic number.

647729506 is a deficient number, since it is larger than the sum of its proper divisors (324862154).

647729506 is a wasteful number, since it uses less digits than its factorization.

647729506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332468.

The product of its (nonzero) digits is 635040, while the sum is 46.

The square root of 647729506 is about 25450.5305642142. The cubic root of 647729506 is about 865.2293180640.

The spelling of 647729506 in words is "six hundred forty-seven million, seven hundred twenty-nine thousand, five hundred six".