1643762406 has 64 divisors (see below), whose sum is σ = 3956553216. Its totient is φ = 448569600.

The previous prime is 1643762399. The next prime is 1643762423. The reversal of 1643762406 is 6042673461.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11815 + ... + 58541.

It is an arithmetic number, because the mean of its divisors is an integer number (61821144).

Almost surely, 2^1643762406 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1643762406, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1978276608).

1643762406 is an abundant number, since it is smaller than the sum of its proper divisors (2312790810).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1643762406 is a wasteful number, since it uses less digits than its factorization.

1643762406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46797.

The product of its (nonzero) digits is 145152, while the sum is 39.

The square root of 1643762406 is about 40543.3398476248. The cubic root of 1643762406 is about 1180.1748295014.

The spelling of 1643762406 in words is "one billion, six hundred forty-three million, seven hundred sixty-two thousand, four hundred six".