1640605031 has 4 divisors (see below), whose sum is σ = 1766805432. Its totient is φ = 1514404632.

The previous prime is 1640604997. The next prime is 1640605039. The reversal of 1640605031 is 1305060461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1305060461 = 563 ⋅2318047.

It is not a de Polignac number, because 1640605031 - 2¹⁴ = 1640588647 is a prime.

It is a super-2 number, since 2×1640605031² = 5383169735485021922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640605039) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63100181 + ... + 63100206.

It is an arithmetic number, because the mean of its divisors is an integer number (441701358).

Almost surely, 2^1640605031 is an apocalyptic number.

1640605031 is a deficient number, since it is larger than the sum of its proper divisors (126200401).

1640605031 is a wasteful number, since it uses less digits than its factorization.

1640605031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126200400.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 1640605031 is about 40504.3828616114. The cubic root of 1640605031 is about 1179.4187099102.

Adding to 1640605031 its reverse (1305060461), we get a palindrome (2945665492).

The spelling of 1640605031 in words is "one billion, six hundred forty million, six hundred five thousand, thirty-one".