21911498293187 has 4 divisors (see below), whose sum is σ = 23064735045480. Its totient is φ = 20758261540896.

The previous prime is 21911498293171. The next prime is 21911498293241. The reversal of 21911498293187 is 78139289411912.

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 21911498293187 - 2⁴ = 21911498293171 is a prime.

It is a super-2 number, since 2×21911498293187² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21911498293147) 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, 576618376118 + ... + 576618376155.

It is an arithmetic number, because the mean of its divisors is an integer number (5766183761370).

Almost surely, 2^{21911498293187} is an apocalyptic number.

21911498293187 is a deficient number, since it is larger than the sum of its proper divisors (1153236752293).

21911498293187 is a wasteful number, since it uses less digits than its factorization.

21911498293187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1153236752292.

The product of its digits is 15676416, while the sum is 65.

The spelling of 21911498293187 in words is "twenty-one trillion, nine hundred eleven billion, four hundred ninety-eight million, two hundred ninety-three thousand, one hundred eighty-seven".