1640377547 has 4 divisors (see below), whose sum is σ = 1696942320. Its totient is φ = 1583812776.

The previous prime is 1640377537. The next prime is 1640377577. The reversal of 1640377547 is 7457730461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7457730461 = 6551 ⋅1138411.

It is a cyclic number.

It is not a de Polignac number, because 1640377547 - 2¹⁰ = 1640376523 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1640377498 and 1640377507.

It is not an unprimeable number, because it can be changed into a prime (1640377537) 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, 28282343 + ... + 28282400.

It is an arithmetic number, because the mean of its divisors is an integer number (424235580).

Almost surely, 2^1640377547 is an apocalyptic number.

1640377547 is a deficient number, since it is larger than the sum of its proper divisors (56564773).

1640377547 is an equidigital number, since it uses as much as digits as its factorization.

1640377547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56564772.

The product of its (nonzero) digits is 493920, while the sum is 44.

The square root of 1640377547 is about 40501.5746237106. The cubic root of 1640377547 is about 1179.3641952073.

The spelling of 1640377547 in words is "one billion, six hundred forty million, three hundred seventy-seven thousand, five hundred forty-seven".