1640253649 has 8 divisors (see below), whose sum is σ = 1650021408. Its totient is φ = 1630508640.

The previous prime is 1640253613. The next prime is 1640253661. The reversal of 1640253649 is 9463520461.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1640253649 - 2²³ = 1631865041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640253149) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 151629 + ... + 162085.

It is an arithmetic number, because the mean of its divisors is an integer number (206252676).

Almost surely, 2^1640253649 is an apocalyptic number.

It is an amenable number.

1640253649 is a deficient number, since it is larger than the sum of its proper divisors (9767759).

1640253649 is a wasteful number, since it uses less digits than its factorization.

1640253649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11375.

The product of its (nonzero) digits is 155520, while the sum is 40.

The square root of 1640253649 is about 40500.0450493577. The cubic root of 1640253649 is about 1179.3345019325.

The spelling of 1640253649 in words is "one billion, six hundred forty million, two hundred fifty-three thousand, six hundred forty-nine".