21620543 has 8 divisors (see below), whose sum is σ = 25377312. Its totient is φ = 18030816.

The previous prime is 21620531. The next prime is 21620561. The reversal of 21620543 is 34502612.

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 21620543 - 2⁶ = 21620479 is a prime.

It is a super-2 number, since 2×21620543² = 934895759229698, which 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 (21620513) 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, 41480 + ... + 41997.

It is an arithmetic number, because the mean of its divisors is an integer number (3172164).

Almost surely, 2^21620543 is an apocalyptic number.

21620543 is a deficient number, since it is larger than the sum of its proper divisors (3756769).

21620543 is an equidigital number, since it uses as much as digits as its factorization.

21620543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83521.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 21620543 is about 4649.7895651309. The cubic root of 21620543 is about 278.5835910785.

The spelling of 21620543 in words is "twenty-one million, six hundred twenty thousand, five hundred forty-three".