21545342 has 32 divisors (see below), whose sum is σ = 41513472. Its totient is φ = 8151264.

The previous prime is 21545339. The next prime is 21545351. The reversal of 21545342 is 24354512.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1613 + ... + 6759.

It is an arithmetic number, because the mean of its divisors is an integer number (1297296).

Almost surely, 2^21545342 is an apocalyptic number.

21545342 is a deficient number, since it is larger than the sum of its proper divisors (19968130).

21545342 is a wasteful number, since it uses less digits than its factorization.

21545342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5192.

The product of its digits is 4800, while the sum is 26.

The square root of 21545342 is about 4641.6960262387. The cubic root of 21545342 is about 278.2602242236.

Adding to 21545342 its reverse (24354512), we get a palindrome (45899854).

The spelling of 21545342 in words is "twenty-one million, five hundred forty-five thousand, three hundred forty-two".