1640450629 has 2 divisors, whose sum is σ = 1640450630. Its totient is φ = 1640450628.

The previous prime is 1640450621. The next prime is 1640450639. The reversal of 1640450629 is 9260540461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 932997025 + 707453604 = 30545^2 + 26598^2 .

It is a cyclic number.

It is not a de Polignac number, because 1640450629 - 2³ = 1640450621 is a prime.

It is a super-4 number, since 4×1640450629⁴ (a number of 38 digits) contains 4444 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1640450621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820225314 + 820225315.

It is an arithmetic number, because the mean of its divisors is an integer number (820225315).

Almost surely, 2^1640450629 is an apocalyptic number.

It is an amenable number.

1640450629 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640450629 is an equidigital number, since it uses as much as digits as its factorization.

1640450629 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 1640450629 is about 40502.4768254980. The cubic root of 1640450629 is about 1179.3817092677.

The spelling of 1640450629 in words is "one billion, six hundred forty million, four hundred fifty thousand, six hundred twenty-nine".