647551749 has 32 divisors (see below), whose sum is σ = 1001566720. Its totient is φ = 368722368.

The previous prime is 647551747. The next prime is 647551753. The reversal of 647551749 is 947155746.

It is not a de Polignac number, because 647551749 - 2¹ = 647551747 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 647551698 and 647551707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647551741) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21702 + ... + 42024.

It is an arithmetic number, because the mean of its divisors is an integer number (31298960).

Almost surely, 2^647551749 is an apocalyptic number.

It is an amenable number.

647551749 is a deficient number, since it is larger than the sum of its proper divisors (354014971).

647551749 is a wasteful number, since it uses less digits than its factorization.

647551749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20401.

The product of its digits is 1058400, while the sum is 48.

The square root of 647551749 is about 25447.0381184137. The cubic root of 647551749 is about 865.1501622652.

The spelling of 647551749 in words is "six hundred forty-seven million, five hundred fifty-one thousand, seven hundred forty-nine".