21707524457 has 4 divisors (see below), whose sum is σ = 21804867840. Its totient is φ = 21610181076.

The previous prime is 21707524429. The next prime is 21707524469. The reversal of 21707524457 is 75442570712.

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 21707524457 - 2⁶ = 21707524393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21707529457) 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, 48671357 + ... + 48671802.

It is an arithmetic number, because the mean of its divisors is an integer number (5451216960).

Almost surely, 2^21707524457 is an apocalyptic number.

It is an amenable number.

21707524457 is a deficient number, since it is larger than the sum of its proper divisors (97343383).

21707524457 is an equidigital number, since it uses as much as digits as its factorization.

21707524457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97343382.

The product of its (nonzero) digits is 548800, while the sum is 44.

The spelling of 21707524457 in words is "twenty-one billion, seven hundred seven million, five hundred twenty-four thousand, four hundred fifty-seven".