1640641525 has 12 divisors (see below), whose sum is σ = 2154066372. Its totient is φ = 1235306240.

The previous prime is 1640641501. The next prime is 1640641537. The reversal of 1640641525 is 5251460461.

It can be written as a sum of positive squares in 6 ways, for example, as 157929489 + 1482712036 = 12567^2 + 38506^2 .

It is not a de Polignac number, because 1640641525 - 2¹³ = 1640633333 is a prime.

It is a super-2 number, since 2×1640641525² = 5383409227108651250, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1929742 + ... + 1930591.

It is an arithmetic number, because the mean of its divisors is an integer number (179505531).

Almost surely, 2^1640641525 is an apocalyptic number.

It is an amenable number.

1640641525 is a deficient number, since it is larger than the sum of its proper divisors (513424847).

1640641525 is a wasteful number, since it uses less digits than its factorization.

1640641525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3860360 (or 3860355 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 34.

The square root of 1640641525 is about 40504.8333535641. The cubic root of 1640641525 is about 1179.4274549334.

The spelling of 1640641525 in words is "one billion, six hundred forty million, six hundred forty-one thousand, five hundred twenty-five".