1640574121 has 2 divisors, whose sum is σ = 1640574122. Its totient is φ = 1640574120.

The previous prime is 1640574101. The next prime is 1640574139. The reversal of 1640574121 is 1214750461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1329404521 + 311169600 = 36461^2 + 17640^2 .

It is an emirp because it is prime and its reverse (1214750461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1640574121 - 2²¹ = 1638476969 is a prime.

It is not a weakly prime, because it can be changed into another prime (1640574101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820287060 + 820287061.

It is an arithmetic number, because the mean of its divisors is an integer number (820287061).

Almost surely, 2^1640574121 is an apocalyptic number.

It is an amenable number.

1640574121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640574121 is an equidigital number, since it uses as much as digits as its factorization.

1640574121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 1640574121 is about 40504.0012961683. The cubic root of 1640574121 is about 1179.4113028743.

The spelling of 1640574121 in words is "one billion, six hundred forty million, five hundred seventy-four thousand, one hundred twenty-one".