101212661 has 4 divisors (see below), whose sum is σ = 110413824. Its totient is φ = 92011500.

The previous prime is 101212651. The next prime is 101212663. The reversal of 101212661 is 166212101.

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: 166212101 = 11 ⋅15110191.

It is a cyclic number.

It is not a de Polignac number, because 101212661 - 2⁶ = 101212597 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 (101212663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4600565 + ... + 4600586.

It is an arithmetic number, because the mean of its divisors is an integer number (27603456).

Almost surely, 2^101212661 is an apocalyptic number.

101212661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

101212661 is a deficient number, since it is larger than the sum of its proper divisors (9201163).

101212661 is an equidigital number, since it uses as much as digits as its factorization.

101212661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9201162.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 101212661 is about 10060.4503378328. The cubic root of 101212661 is about 466.0275745501.

Adding to 101212661 its reverse (166212101), we get a palindrome (267424762).

The spelling of 101212661 in words is "one hundred one million, two hundred twelve thousand, six hundred sixty-one".