1640213325 has 18 divisors (see below), whose sum is σ = 2937804714. Its totient is φ = 874780320.

The previous prime is 1640213299. The next prime is 1640213339. The reversal of 1640213325 is 5233120461.

1640213325 is a `hidden beast` number, since 1 + 640 + 2 + 13 + 3 + 2 + 5 = 666.

1640213325 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 206152164 + 1434061161 = 14358^2 + 37869^2 .

It is not a de Polignac number, because 1640213325 - 2¹² = 1640209229 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3644694 + ... + 3645143.

It is an arithmetic number, because the mean of its divisors is an integer number (163211373).

Almost surely, 2^1640213325 is an apocalyptic number.

1640213325 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1640213325 is a deficient number, since it is larger than the sum of its proper divisors (1297591389).

1640213325 is a wasteful number, since it uses less digits than its factorization.

1640213325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7289853 (or 7289845 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 1640213325 is about 40499.5472196912. The cubic root of 1640213325 is about 1179.3248375991.

Adding to 1640213325 its reverse (5233120461), we get a palindrome (6873333786).

The spelling of 1640213325 in words is "one billion, six hundred forty million, two hundred thirteen thousand, three hundred twenty-five".