21154342 has 32 divisors (see below), whose sum is σ = 36578304. Its totient is φ = 9081600.

The previous prime is 21154339. The next prime is 21154381. The reversal of 21154342 is 24345112.

It is a Harshad number since it is a multiple of its sum of digits (22).

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, 48867 + ... + 49297.

It is an arithmetic number, because the mean of its divisors is an integer number (1143072).

Almost surely, 2^21154342 is an apocalyptic number.

21154342 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21154342 is a deficient number, since it is larger than the sum of its proper divisors (15423962).

21154342 is a wasteful number, since it uses less digits than its factorization.

21154342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 564.

The product of its digits is 960, while the sum is 22.

The square root of 21154342 is about 4599.3849588831. The cubic root of 21154342 is about 276.5666698830.

Adding to 21154342 its reverse (24345112), we get a palindrome (45499454).

The spelling of 21154342 in words is "twenty-one million, one hundred fifty-four thousand, three hundred forty-two".