21502242 has 24 divisors (see below), whose sum is σ = 46715760. Its totient is φ = 7147800.

The previous prime is 21502241. The next prime is 21502267. The reversal of 21502242 is 24220512.

It is a super-2 number, since 2×21502242² = 924692822053128, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (21502241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6117 + ... + 8967.

It is an arithmetic number, because the mean of its divisors is an integer number (1946490).

Almost surely, 2^21502242 is an apocalyptic number.

21502242 is an abundant number, since it is smaller than the sum of its proper divisors (25213518).

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

21502242 is a wasteful number, since it uses less digits than its factorization.

21502242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3278 (or 3275 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 21502242 is about 4637.0510025230. The cubic root of 21502242 is about 278.0745534394.

Adding to 21502242 its reverse (24220512), we get a palindrome (45722754).

The spelling of 21502242 in words is "twenty-one million, five hundred two thousand, two hundred forty-two".