21550379 has 8 divisors (see below), whose sum is σ = 23036832. Its totient is φ = 20109760.

The previous prime is 21550357. The next prime is 21550387. The reversal of 21550379 is 97305512.

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 21550379 - 2¹⁶ = 21484843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21550079) 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, 10484 + ... + 12369.

It is an arithmetic number, because the mean of its divisors is an integer number (2879604).

Almost surely, 2^21550379 is an apocalyptic number.

21550379 is a deficient number, since it is larger than the sum of its proper divisors (1486453).

21550379 is a wasteful number, since it uses less digits than its factorization.

21550379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22917.

The product of its (nonzero) digits is 9450, while the sum is 32.

The square root of 21550379 is about 4642.2385763767. The cubic root of 21550379 is about 278.2819069852.

The spelling of 21550379 in words is "twenty-one million, five hundred fifty thousand, three hundred seventy-nine".