1061665638 has 16 divisors (see below), whose sum is σ = 2316361536. Its totient is φ = 321716840.

The previous prime is 1061665637. The next prime is 1061665643. The reversal of 1061665638 is 8365661601.

It is a super-2 number, since 2×1061665638² = 2254267853819894088, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 1061665638.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1061665637) 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, 8042856 + ... + 8042987.

It is an arithmetic number, because the mean of its divisors is an integer number (144772596).

Almost surely, 2^1061665638 is an apocalyptic number.

1061665638 is an abundant number, since it is smaller than the sum of its proper divisors (1254695898).

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

1061665638 is a wasteful number, since it uses less digits than its factorization.

1061665638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16085859.

The product of its (nonzero) digits is 155520, while the sum is 42.

The square root of 1061665638 is about 32583.2109835725. The cubic root of 1061665638 is about 1020.1466013813.

The spelling of 1061665638 in words is "one billion, sixty-one million, six hundred sixty-five thousand, six hundred thirty-eight".