21499071 has 8 divisors (see below), whose sum is σ = 31271424. Its totient is φ = 13029720.

The previous prime is 21499057. The next prime is 21499081. The reversal of 21499071 is 17099412.

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

It is not a de Polignac number, because 21499071 - 2⁵ = 21499039 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 651487 = 21499071 / (2 + 1 + 4 + 9 + 9 + 0 + 7 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21499021) 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, 325711 + ... + 325776.

It is an arithmetic number, because the mean of its divisors is an integer number (3908928).

Almost surely, 2^21499071 is an apocalyptic number.

21499071 is a deficient number, since it is larger than the sum of its proper divisors (9772353).

21499071 is a wasteful number, since it uses less digits than its factorization.

21499071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 651501.

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 21499071 is about 4636.7090700194. The cubic root of 21499071 is about 278.0608832718.

The spelling of 21499071 in words is "twenty-one million, four hundred ninety-nine thousand, seventy-one".