647543540 has 24 divisors (see below), whose sum is σ = 1554104832. Its totient is φ = 222014880.

The previous prime is 647543537. The next prime is 647543557. The reversal of 647543540 is 45345746.

It is a happy number.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 647543494 and 647543503.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2312516 + ... + 2312795.

It is an arithmetic number, because the mean of its divisors is an integer number (64754368).

Almost surely, 2^647543540 is an apocalyptic number.

It is an amenable number.

647543540 is an abundant number, since it is smaller than the sum of its proper divisors (906561292).

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

647543540 is a wasteful number, since it uses less digits than its factorization.

647543540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4625327 (or 4625325 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 38.

The square root of 647543540 is about 25446.8768221171. The cubic root of 647543540 is about 865.1465064196.

The spelling of 647543540 in words is "six hundred forty-seven million, five hundred forty-three thousand, five hundred forty".