21453770769 has 4 divisors (see below), whose sum is σ = 28605027696. Its totient is φ = 14302513844.

The previous prime is 21453770761. The next prime is 21453770797. The reversal of 21453770769 is 96707735412.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21453770769 - 2³ = 21453770761 is a prime.

It is a super-2 number, since 2×21453770769² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21453770761) 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, 3575628459 + ... + 3575628464.

It is an arithmetic number, because the mean of its divisors is an integer number (7151256924).

Almost surely, 2^21453770769 is an apocalyptic number.

It is an amenable number.

21453770769 is a deficient number, since it is larger than the sum of its proper divisors (7151256927).

21453770769 is an equidigital number, since it uses as much as digits as its factorization.

21453770769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7151256926.

The product of its (nonzero) digits is 2222640, while the sum is 51.

The spelling of 21453770769 in words is "twenty-one billion, four hundred fifty-three million, seven hundred seventy thousand, seven hundred sixty-nine".