21450039 has 16 divisors (see below), whose sum is σ = 32612832. Its totient is φ = 12423168.

The previous prime is 21450029. The next prime is 21450061. The reversal of 21450039 is 93005412.

It is not a de Polignac number, because 21450039 - 2¹¹ = 21447991 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21450019) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15514 + ... + 16839.

It is an arithmetic number, because the mean of its divisors is an integer number (2038302).

Almost surely, 2^21450039 is an apocalyptic number.

21450039 is a deficient number, since it is larger than the sum of its proper divisors (11162793).

21450039 is a wasteful number, since it uses less digits than its factorization.

21450039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32386.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 21450039 is about 4631.4186811386. The cubic root of 21450039 is about 277.8493352299.

The spelling of 21450039 in words is "twenty-one million, four hundred fifty thousand, thirty-nine".