1681265690 has 32 divisors (see below), whose sum is σ = 3260975760. Its totient is φ = 620411904.

The previous prime is 1681265671. The next prime is 1681265693. The reversal of 1681265690 is 965621861.

It can be written as a sum of positive squares in 8 ways, for example, as 701137441 + 980128249 = 26479^2 + 31307^2 .

It is a super-2 number, since 2×1681265690² = 5653308640742352200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1681265693) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 336692 + ... + 341648.

Almost surely, 2^1681265690 is an apocalyptic number.

1681265690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1681265690 is a deficient number, since it is larger than the sum of its proper divisors (1579710070).

1681265690 is a wasteful number, since it uses less digits than its factorization.

1681265690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7586.

The product of its (nonzero) digits is 155520, while the sum is 44.

The square root of 1681265690 is about 41003.2399939322. The cubic root of 1681265690 is about 1189.0828538099.

The spelling of 1681265690 in words is "one billion, six hundred eighty-one million, two hundred sixty-five thousand, six hundred ninety".