1640453071 has 4 divisors (see below), whose sum is σ = 1693370944. Its totient is φ = 1587535200.

The previous prime is 1640453041. The next prime is 1640453099. The reversal of 1640453071 is 1703540461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1703540461 = 7 ⋅243362923.

It is a cyclic number.

It is not a de Polignac number, because 1640453071 - 2²¹ = 1638355919 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 52917841 = 1640453071 / (1 + 6 + 4 + 0 + 4 + 5 + 3 + 0 + 7 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640453011) 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, 26458890 + ... + 26458951.

It is an arithmetic number, because the mean of its divisors is an integer number (423342736).

Almost surely, 2^1640453071 is an apocalyptic number.

1640453071 is a deficient number, since it is larger than the sum of its proper divisors (52917873).

1640453071 is an equidigital number, since it uses as much as digits as its factorization.

1640453071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52917872.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 1640453071 is about 40502.5069717913. The cubic root of 1640453071 is about 1179.3822944826.

The spelling of 1640453071 in words is "one billion, six hundred forty million, four hundred fifty-three thousand, seventy-one".