21620142 has 32 divisors (see below), whose sum is σ = 49167360. Its totient is φ = 7038360.

The previous prime is 21620129. The next prime is 21620153. The reversal of 21620142 is 24102612.

21620142 is a `hidden beast` number, since 2 + 1 + 620 + 1 + 42 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

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, 2334 + ... + 6977.

It is an arithmetic number, because the mean of its divisors is an integer number (1536480).

Almost surely, 2^21620142 is an apocalyptic number.

21620142 is an abundant number, since it is smaller than the sum of its proper divisors (27547218).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21620142 is a wasteful number, since it uses less digits than its factorization.

21620142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9365 (or 9359 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21620142 is about 4649.7464447000. The cubic root of 21620142 is about 278.5818687550.

Adding to 21620142 its reverse (24102612), we get a palindrome (45722754).

The spelling of 21620142 in words is "twenty-one million, six hundred twenty thousand, one hundred forty-two".