101287661 has 4 divisors (see below), whose sum is σ = 103643232. Its totient is φ = 98932092.

The previous prime is 101287657. The next prime is 101287723. The reversal of 101287661 is 166782101.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 166782101 = 373 ⋅447137.

It is a cyclic number.

It is not a de Polignac number, because 101287661 - 2² = 101287657 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101287631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1177721 + ... + 1177806.

It is an arithmetic number, because the mean of its divisors is an integer number (25910808).

Almost surely, 2^101287661 is an apocalyptic number.

It is an amenable number.

101287661 is a deficient number, since it is larger than the sum of its proper divisors (2355571).

101287661 is an equidigital number, since it uses as much as digits as its factorization.

101287661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2355570.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 101287661 is about 10064.1771148962. The cubic root of 101287661 is about 466.1426571164.

The spelling of 101287661 in words is "one hundred one million, two hundred eighty-seven thousand, six hundred sixty-one".