1640471631 has 4 divisors (see below), whose sum is σ = 2187295512. Its totient is φ = 1093647752.

The previous prime is 1640471621. The next prime is 1640471639. The reversal of 1640471631 is 1361740461.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1640471631 - 2¹⁴ = 1640455247 is a prime.

It is a super-2 number, since 2×1640471631² = 5382294344231600322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1640471592 and 1640471601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640471639) 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 3 ways as a sum of consecutive naturals, for example, 273411936 + ... + 273411941.

It is an arithmetic number, because the mean of its divisors is an integer number (546823878).

Almost surely, 2^1640471631 is an apocalyptic number.

1640471631 is a deficient number, since it is larger than the sum of its proper divisors (546823881).

1640471631 is an equidigital number, since it uses as much as digits as its factorization.

1640471631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546823880.

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 1640471631 is about 40502.7360927629. The cubic root of 1640471631 is about 1179.3867422890.

The spelling of 1640471631 in words is "one billion, six hundred forty million, four hundred seventy-one thousand, six hundred thirty-one".