21407379 has 8 divisors (see below), whose sum is σ = 32620800. Its totient is φ = 12232776.

The previous prime is 21407377. The next prime is 21407381. The reversal of 21407379 is 97370412.

It is an interprime number because it is at equal distance from previous prime (21407377) and next prime (21407381).

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

It is not a de Polignac number, because 21407379 - 2¹ = 21407377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21407377) 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, 509679 + ... + 509720.

It is an arithmetic number, because the mean of its divisors is an integer number (4077600).

Almost surely, 2^21407379 is an apocalyptic number.

21407379 is a deficient number, since it is larger than the sum of its proper divisors (11213421).

21407379 is a wasteful number, since it uses less digits than its factorization.

21407379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1019409.

The product of its (nonzero) digits is 10584, while the sum is 33.

The square root of 21407379 is about 4626.8108887224. The cubic root of 21407379 is about 277.6650166972.

The spelling of 21407379 in words is "twenty-one million, four hundred seven thousand, three hundred seventy-nine".