21661465732367 has 4 divisors (see below), whose sum is σ = 22603268590320. Its totient is φ = 20719662874416.

The previous prime is 21661465732331. The next prime is 21661465732369. The reversal of 21661465732367 is 76323756416612.

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 21661465732367 - 2¹⁴ = 21661465715983 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 (21661465732369) 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, 470901428942 + ... + 470901428987.

It is an arithmetic number, because the mean of its divisors is an integer number (5650817147580).

Almost surely, 2^{21661465732367} is an apocalyptic number.

21661465732367 is a deficient number, since it is larger than the sum of its proper divisors (941802857953).

21661465732367 is an equidigital number, since it uses as much as digits as its factorization.

21661465732367 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 941802857952.

The product of its digits is 45722880, while the sum is 59.

The spelling of 21661465732367 in words is "twenty-one trillion, six hundred sixty-one billion, four hundred sixty-five million, seven hundred thirty-two thousand, three hundred sixty-seven".