1640971 has 2 divisors, whose sum is σ = 1640972. Its totient is φ = 1640970.

The previous prime is 1640953. The next prime is 1641007. The reversal of 1640971 is 1790461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1640971 - 2⁵ = 1640939 is a prime.

It is a super-3 number, since 3×1640971³ = 13256350333479655833, which contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (1640941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820485 + 820486.

It is an arithmetic number, because the mean of its divisors is an integer number (820486).

2^1640971 is an apocalyptic number.

1640971 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640971 is an equidigital number, since it uses as much as digits as its factorization.

1640971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 1640971 is about 1281.0039031947. The cubic root of 1640971 is about 117.9506400851.

The spelling of 1640971 in words is "one million, six hundred forty thousand, nine hundred seventy-one".