21866903357407 has 4 divisors (see below), whose sum is σ = 21867836627536. Its totient is φ = 21865970087280.

The previous prime is 21866903357399. The next prime is 21866903357437. The reversal of 21866903357407 is 70475330966812.

It is a happy number.

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 21866903357407 - 2³ = 21866903357399 is a prime.

It is a super-2 number, since 2×21866903357407² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21866903357437) 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, 466599918 + ... + 466646779.

It is an arithmetic number, because the mean of its divisors is an integer number (5466959156884).

It is a 1-persistent number, because it is pandigital, but 2⋅21866903357407 = 43733806714814 is not.

Almost surely, 2^{21866903357407} is an apocalyptic number.

21866903357407 is a deficient number, since it is larger than the sum of its proper divisors (933270129).

21866903357407 is an equidigital number, since it uses as much as digits as its factorization.

21866903357407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 933270128.

The product of its (nonzero) digits is 45722880, while the sum is 61.

The spelling of 21866903357407 in words is "twenty-one trillion, eight hundred sixty-six billion, nine hundred three million, three hundred fifty-seven thousand, four hundred seven".