21458770687 has 8 divisors (see below), whose sum is σ = 21708140400. Its totient is φ = 21209584704.

The previous prime is 21458770657. The next prime is 21458770733. The reversal of 21458770687 is 78607785412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21458770687 - 2¹⁵ = 21458737919 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 (21458770657) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 196389 + ... + 285457.

It is an arithmetic number, because the mean of its divisors is an integer number (2713517550).

Almost surely, 2^21458770687 is an apocalyptic number.

21458770687 is a deficient number, since it is larger than the sum of its proper divisors (249369713).

21458770687 is an equidigital number, since it uses as much as digits as its factorization.

21458770687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91865.

The product of its (nonzero) digits is 5268480, while the sum is 55.

The spelling of 21458770687 in words is "twenty-one billion, four hundred fifty-eight million, seven hundred seventy thousand, six hundred eighty-seven".