647542638 has 12 divisors (see below), whose sum is σ = 1403009088. Its totient is φ = 215847540.

The previous prime is 647542603. The next prime is 647542639. The reversal of 647542638 is 836245746.

647542638 is a `hidden beast` number, since 6 + 4 + 7 + 5 + 4 + 2 + 638 = 666.

It is a super-2 number, since 2×647542638² = 838622936055998088, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 647542593 and 647542602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647542639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17987278 + ... + 17987313.

It is an arithmetic number, because the mean of its divisors is an integer number (116917424).

Almost surely, 2^647542638 is an apocalyptic number.

647542638 is an abundant number, since it is smaller than the sum of its proper divisors (755466450).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

647542638 is a wasteful number, since it uses less digits than its factorization.

647542638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35974599 (or 35974596 counting only the distinct ones).

The product of its digits is 967680, while the sum is 45.

The square root of 647542638 is about 25446.8590989143. The cubic root of 647542638 is about 865.1461047156.

The spelling of 647542638 in words is "six hundred forty-seven million, five hundred forty-two thousand, six hundred thirty-eight".