1640251345 has 16 divisors (see below), whose sum is σ = 1979182080. Its totient is φ = 1304967744.

The previous prime is 1640251337. The next prime is 1640251391. The reversal of 1640251345 is 5431520461.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1640251345 - 2³ = 1640251337 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1139136 + ... + 1140574.

It is an arithmetic number, because the mean of its divisors is an integer number (123698880).

Almost surely, 2^1640251345 is an apocalyptic number.

It is an amenable number.

1640251345 is a deficient number, since it is larger than the sum of its proper divisors (338930735).

1640251345 is a wasteful number, since it uses less digits than its factorization.

1640251345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2544.

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 1640251345 is about 40500.0166049349. The cubic root of 1640251345 is about 1179.3339497439. Note that the first 3 decimals are identical.

The spelling of 1640251345 in words is "one billion, six hundred forty million, two hundred fifty-one thousand, three hundred forty-five".