21953087 has 8 divisors (see below), whose sum is σ = 24457440. Its totient is φ = 19565280.

The previous prime is 21953051. The next prime is 21953143. The reversal of 21953087 is 78035912.

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 21953087 - 2¹⁸ = 21690943 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21953387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28739 + ... + 29492.

It is an arithmetic number, because the mean of its divisors is an integer number (3057180).

Almost surely, 2^21953087 is an apocalyptic number.

21953087 is a deficient number, since it is larger than the sum of its proper divisors (2504353).

21953087 is a wasteful number, since it uses less digits than its factorization.

21953087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58273.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 21953087 is about 4685.4121483601. The cubic root of 21953087 is about 280.0046215224.

Adding to 21953087 its reverse (78035912), we get a palindrome (99988999).

The spelling of 21953087 in words is "twenty-one million, nine hundred fifty-three thousand, eighty-seven".