21377121 has 4 divisors (see below), whose sum is σ = 28502832. Its totient is φ = 14251412.

The previous prime is 21377119. The next prime is 21377129. The reversal of 21377121 is 12177312.

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 21377121 - 2¹ = 21377119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21377091 and 21377100.

It is not an unprimeable number, because it can be changed into a prime (21377129) 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, 3562851 + ... + 3562856.

It is an arithmetic number, because the mean of its divisors is an integer number (7125708).

Almost surely, 2^21377121 is an apocalyptic number.

It is an amenable number.

21377121 is a deficient number, since it is larger than the sum of its proper divisors (7125711).

21377121 is an equidigital number, since it uses as much as digits as its factorization.

21377121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7125710.

The product of its digits is 588, while the sum is 24.

The square root of 21377121 is about 4623.5398776262. The cubic root of 21377121 is about 277.5341342639.

The spelling of 21377121 in words is "twenty-one million, three hundred seventy-seven thousand, one hundred twenty-one".