101212506491 has 4 divisors (see below), whose sum is σ = 101294328672. Its totient is φ = 101130684312.

The previous prime is 101212506407. The next prime is 101212506517. The reversal of 101212506491 is 194605212101.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 101212506491 - 2³⁴ = 84032637307 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (101212506191) 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, 40909235 + ... + 40911708.

It is an arithmetic number, because the mean of its divisors is an integer number (25323582168).

Almost surely, 2^101212506491 is an apocalyptic number.

101212506491 is a deficient number, since it is larger than the sum of its proper divisors (81822181).

101212506491 is an equidigital number, since it uses as much as digits as its factorization.

101212506491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81822180.

The product of its (nonzero) digits is 4320, while the sum is 32.

Adding to 101212506491 its reverse (194605212101), we get a palindrome (295817718592).

The spelling of 101212506491 in words is "one hundred one billion, two hundred twelve million, five hundred six thousand, four hundred ninety-one".