21731454526667 has 4 divisors (see below), whose sum is σ = 21750302276760. Its totient is φ = 21712606776576.

The previous prime is 21731454526597. The next prime is 21731454526813. The reversal of 21731454526667 is 76662545413712.

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 21731454526667 - 2³⁰ = 21730380784843 is a prime.

It is a super-2 number, since 2×21731454526667² (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 (21731454526267) 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, 9423873317 + ... + 9423875622.

It is an arithmetic number, because the mean of its divisors is an integer number (5437575569190).

Almost surely, 2^{21731454526667} is an apocalyptic number.

21731454526667 is a deficient number, since it is larger than the sum of its proper divisors (18847750093).

21731454526667 is a wasteful number, since it uses less digits than its factorization.

21731454526667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18847750092.

The product of its digits is 50803200, while the sum is 59.

The spelling of 21731454526667 in words is "twenty-one trillion, seven hundred thirty-one billion, four hundred fifty-four million, five hundred twenty-six thousand, six hundred sixty-seven".