21577641 has 8 divisors (see below), whose sum is σ = 30462624. Its totient is φ = 13538880.

The previous prime is 21577639. The next prime is 21577649. The reversal of 21577641 is 14677512.

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

It is not a de Polignac number, because 21577641 - 2¹ = 21577639 is a prime.

It is a super-2 number, since 2×21577641² = 931189182249762, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21577649) 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, 211495 + ... + 211596.

It is an arithmetic number, because the mean of its divisors is an integer number (3807828).

Almost surely, 2^21577641 is an apocalyptic number.

It is an amenable number.

21577641 is a deficient number, since it is larger than the sum of its proper divisors (8884983).

21577641 is a wasteful number, since it uses less digits than its factorization.

21577641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423111.

The product of its digits is 11760, while the sum is 33.

The square root of 21577641 is about 4645.1739472274. The cubic root of 21577641 is about 278.3992030587.

The spelling of 21577641 in words is "twenty-one million, five hundred seventy-seven thousand, six hundred forty-one".