647420731 has 8 divisors (see below), whose sum is σ = 653696064. Its totient is φ = 641155200.

The previous prime is 647420701. The next prime is 647420749. The reversal of 647420731 is 137024746.

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

It is a cyclic number.

It is not a de Polignac number, because 647420731 - 2⁵ = 647420699 is a prime.

It is a super-2 number, since 2×647420731² = 838307205857148722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647420701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 264445 + ... + 266881.

It is an arithmetic number, because the mean of its divisors is an integer number (81712008).

Almost surely, 2^647420731 is an apocalyptic number.

647420731 is a deficient number, since it is larger than the sum of its proper divisors (6275333).

647420731 is a wasteful number, since it uses less digits than its factorization.

647420731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4901.

The product of its (nonzero) digits is 28224, while the sum is 34.

The square root of 647420731 is about 25444.4636610796. The cubic root of 647420731 is about 865.0918102289.

The spelling of 647420731 in words is "six hundred forty-seven million, four hundred twenty thousand, seven hundred thirty-one".