1656640534 has 4 divisors (see below), whose sum is σ = 2484960804. Its totient is φ = 828320266.

The previous prime is 1656640519. The next prime is 1656640543. The reversal of 1656640534 is 4350466561.

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

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 414160132 + ... + 414160135.

It is an arithmetic number, because the mean of its divisors is an integer number (621240201).

Almost surely, 2^1656640534 is an apocalyptic number.

1656640534 is a deficient number, since it is larger than the sum of its proper divisors (828320270).

1656640534 is an equidigital number, since it uses as much as digits as its factorization.

1656640534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 828320269.

The product of its (nonzero) digits is 259200, while the sum is 40.

The square root of 1656640534 is about 40701.8492700270. The cubic root of 1656640534 is about 1183.2488592126.

The spelling of 1656640534 in words is "one billion, six hundred fifty-six million, six hundred forty thousand, five hundred thirty-four".