647765141 has 4 divisors (see below), whose sum is σ = 670101900. Its totient is φ = 625428384.

The previous prime is 647765137. The next prime is 647765143. The reversal of 647765141 is 141567746.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 485100625 + 162664516 = 22025^2 + 12754^2 .

It is not a de Polignac number, because 647765141 - 2² = 647765137 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647765143) 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, 11168336 + ... + 11168393.

It is an arithmetic number, because the mean of its divisors is an integer number (167525475).

Almost surely, 2^647765141 is an apocalyptic number.

It is an amenable number.

647765141 is a deficient number, since it is larger than the sum of its proper divisors (22336759).

647765141 is a wasteful number, since it uses less digits than its factorization.

647765141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22336758.

The product of its digits is 141120, while the sum is 41.

The square root of 647765141 is about 25451.2306382226. The cubic root of 647765141 is about 865.2451847084.

The spelling of 647765141 in words is "six hundred forty-seven million, seven hundred sixty-five thousand, one hundred forty-one".