1640520899 has 8 divisors (see below), whose sum is σ = 1694345088. Its totient is φ = 1586753280.

The previous prime is 1640520851. The next prime is 1640520913. The reversal of 1640520899 is 9980250461.

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 1640520899 - 2⁸ = 1640520643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640520809) 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, 49409 + ... + 75645.

It is an arithmetic number, because the mean of its divisors is an integer number (211793136).

Almost surely, 2^1640520899 is an apocalyptic number.

1640520899 is a deficient number, since it is larger than the sum of its proper divisors (53824189).

1640520899 is a wasteful number, since it uses less digits than its factorization.

1640520899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28285.

The product of its (nonzero) digits is 155520, while the sum is 44.

The square root of 1640520899 is about 40503.3442940210. The cubic root of 1640520899 is about 1179.3985489433.

The spelling of 1640520899 in words is "one billion, six hundred forty million, five hundred twenty thousand, eight hundred ninety-nine".