1640148971 has 4 divisors (see below), whose sum is σ = 1671095232. Its totient is φ = 1609202712.

The previous prime is 1640148959. The next prime is 1640148977. The reversal of 1640148971 is 1798410461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1798410461 = 29501 ⋅60961.

It is a cyclic number.

It is not a de Polignac number, because 1640148971 - 2¹⁴ = 1640132587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640148977) 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, 15473051 + ... + 15473156.

It is an arithmetic number, because the mean of its divisors is an integer number (417773808).

Almost surely, 2^1640148971 is an apocalyptic number.

1640148971 is a deficient number, since it is larger than the sum of its proper divisors (30946261).

1640148971 is an equidigital number, since it uses as much as digits as its factorization.

1640148971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30946260.

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 1640148971 is about 40498.7527091885. The cubic root of 1640148971 is about 1179.3094137389.

The spelling of 1640148971 in words is "one billion, six hundred forty million, one hundred forty-eight thousand, nine hundred seventy-one".