1640426733 has 12 divisors (see below), whose sum is σ = 2584915008. Its totient is φ = 994197960.

The previous prime is 1640426699. The next prime is 1640426773. The reversal of 1640426733 is 3376240461.

It is a happy number.

1640426733 is a `hidden beast` number, since 1 + 640 + 4 + 2 + 6 + 7 + 3 + 3 = 666.

It is not a de Polignac number, because 1640426733 - 2¹⁷ = 1640295661 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640426773) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8284885 + ... + 8285082.

It is an arithmetic number, because the mean of its divisors is an integer number (215409584).

Almost surely, 2^1640426733 is an apocalyptic number.

It is an amenable number.

1640426733 is a deficient number, since it is larger than the sum of its proper divisors (944488275).

1640426733 is a wasteful number, since it uses less digits than its factorization.

1640426733 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16569984 (or 16569981 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 36.

The square root of 1640426733 is about 40502.1818301187. The cubic root of 1640426733 is about 1179.3759826619.

The spelling of 1640426733 in words is "one billion, six hundred forty million, four hundred twenty-six thousand, seven hundred thirty-three".