21954023 has 8 divisors (see below), whose sum is σ = 27020448. Its totient is φ = 17370144.

The previous prime is 21954019. The next prime is 21954047. The reversal of 21954023 is 32045912.

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 21954023 - 2² = 21954019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21953983 and 21954001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21954323) 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, 120536 + ... + 120717.

It is an arithmetic number, because the mean of its divisors is an integer number (3377556).

Almost surely, 2^21954023 is an apocalyptic number.

21954023 is a deficient number, since it is larger than the sum of its proper divisors (5066425).

21954023 is a wasteful number, since it uses less digits than its factorization.

21954023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241273.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 21954023 is about 4685.5120317848. The cubic root of 21954023 is about 280.0086009263.

Adding to 21954023 its reverse (32045912), we get a palindrome (53999935).

The spelling of 21954023 in words is "twenty-one million, nine hundred fifty-four thousand, twenty-three".