1640406706 has 8 divisors (see below), whose sum is σ = 2461537260. Its totient is φ = 819894288.

The previous prime is 1640406701. The next prime is 1640406739. The reversal of 1640406706 is 6076040461.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1581255225 + 59151481 = 39765^2 + 7691^2 .

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

It is a super-2 number, since 2×1640406706² = 5381868322179540872, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1640406701) 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, 147841 + ... + 158548.

Almost surely, 2^1640406706 is an apocalyptic number.

1640406706 is a deficient number, since it is larger than the sum of its proper divisors (821130554).

1640406706 is a wasteful number, since it uses less digits than its factorization.

1640406706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309068.

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 1640406706 is about 40501.9345957696. The cubic root of 1640406706 is about 1179.3711832077.

The spelling of 1640406706 in words is "one billion, six hundred forty million, four hundred six thousand, seven hundred six".