126561690 has 80 divisors (see below), whose sum is σ = 342242208. Its totient is φ = 33697296.

The previous prime is 126561683. The next prime is 126561697. The reversal of 126561690 is 96165621.

126561690 is a `hidden beast` number, since 1 + 2 + 6 + 561 + 6 + 90 = 666.

It is an interprime number because it is at equal distance from previous prime (126561683) and next prime (126561697).

It is a super-2 number, since 2×126561690² = 32035722751312200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (126561697) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 196509 + ... + 197151.

Almost surely, 2^126561690 is an apocalyptic number.

126561690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 126561690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171121104).

126561690 is an abundant number, since it is smaller than the sum of its proper divisors (215680518).

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

126561690 is an frugal number, since it uses more digits than its factorization.

126561690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677 (or 653 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 126561690 is about 11249.9639999424. The cubic root of 126561690 is about 502.0736414666.

The spelling of 126561690 in words is "one hundred twenty-six million, five hundred sixty-one thousand, six hundred ninety".