21497342 has 4 divisors (see below), whose sum is σ = 32246016. Its totient is φ = 10748670.

The previous prime is 21497339. The next prime is 21497351. The reversal of 21497342 is 24379412.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 21497299 and 21497308.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5374334 + ... + 5374337.

It is an arithmetic number, because the mean of its divisors is an integer number (8061504).

Almost surely, 2^21497342 is an apocalyptic number.

21497342 is a deficient number, since it is larger than the sum of its proper divisors (10748674).

21497342 is a wasteful number, since it uses less digits than its factorization.

21497342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10748673.

The product of its digits is 12096, while the sum is 32.

The square root of 21497342 is about 4636.5226193776. The cubic root of 21497342 is about 278.0534289938.

The spelling of 21497342 in words is "twenty-one million, four hundred ninety-seven thousand, three hundred forty-two".