1640153638 has 16 divisors (see below), whose sum is σ = 2556010080. Its totient is φ = 788393536.

The previous prime is 1640153633. The next prime is 1640153651. The reversal of 1640153638 is 8363510461.

It is a junction number, because it is equal to n+sod(n) for n = 1640153597 and 1640153606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640153633) 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, 47170 + ... + 74197.

It is an arithmetic number, because the mean of its divisors is an integer number (159750630).

Almost surely, 2^1640153638 is an apocalyptic number.

1640153638 is a deficient number, since it is larger than the sum of its proper divisors (915856442).

1640153638 is a wasteful number, since it uses less digits than its factorization.

1640153638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121631.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 1640153638 is about 40498.8103282059. The cubic root of 1640153638 is about 1179.3105323023.

The spelling of 1640153638 in words is "one billion, six hundred forty million, one hundred fifty-three thousand, six hundred thirty-eight".