21346390 has 48 divisors (see below), whose sum is σ = 44113248. Its totient is φ = 7408128.

The previous prime is 21346387. The next prime is 21346397. The reversal of 21346390 is 9364312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21346397) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28359 + ... + 29101.

It is an arithmetic number, because the mean of its divisors is an integer number (919026).

Almost surely, 2^21346390 is an apocalyptic number.

21346390 is an abundant number, since it is smaller than the sum of its proper divisors (22766858).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21346390 is a wasteful number, since it uses less digits than its factorization.

21346390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 793 (or 780 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 21346390 is about 4620.2153629458. The cubic root of 21346390 is about 277.4010793700.

It can be divided in two parts, 21346 and 390, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 21346390 in words is "twenty-one million, three hundred forty-six thousand, three hundred ninety".