101218391 has 4 divisors (see below), whose sum is σ = 107172432. Its totient is φ = 95264352.

The previous prime is 101218373. The next prime is 101218427. The reversal of 101218391 is 193812101.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-101218391 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 101218391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101218291) 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, 2976995 + ... + 2977028.

It is an arithmetic number, because the mean of its divisors is an integer number (26793108).

Almost surely, 2^101218391 is an apocalyptic number.

101218391 is a deficient number, since it is larger than the sum of its proper divisors (5954041).

101218391 is an equidigital number, since it uses as much as digits as its factorization.

101218391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5954040.

The product of its (nonzero) digits is 432, while the sum is 26.

The square root of 101218391 is about 10060.7351123067. The cubic root of 101218391 is about 466.0363688636.

The spelling of 101218391 in words is "one hundred one million, two hundred eighteen thousand, three hundred ninety-one".