1640993451 has 8 divisors (see below), whose sum is σ = 2215687680. Its totient is φ = 1080147432.

The previous prime is 1640993447. The next prime is 1640993467. The reversal of 1640993451 is 1543990461.

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

It is not a de Polignac number, because 1640993451 - 2² = 1640993447 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1640993411) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 3461775 + ... + 3462248.

It is an arithmetic number, because the mean of its divisors is an integer number (276960960).

Almost surely, 2^1640993451 is an apocalyptic number.

1640993451 is a deficient number, since it is larger than the sum of its proper divisors (574694229).

1640993451 is an equidigital number, since it uses as much as digits as its factorization.

1640993451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6924105.

The product of its (nonzero) digits is 116640, while the sum is 42.

The square root of 1640993451 is about 40509.1773676040. The cubic root of 1640993451 is about 1179.5117799785.

The spelling of 1640993451 in words is "one billion, six hundred forty million, nine hundred ninety-three thousand, four hundred fifty-one".