21920010 has 32 divisors (see below), whose sum is σ = 60124032. Its totient is φ = 5010240.

The previous prime is 21919999. The next prime is 21920011. The reversal of 21920010 is 1002912.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (21920011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51981 + ... + 52400.

It is an arithmetic number, because the mean of its divisors is an integer number (1878876).

Almost surely, 2^21920010 is an apocalyptic number.

21920010 is an abundant number, since it is smaller than the sum of its proper divisors (38204022).

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

21920010 is a wasteful number, since it uses less digits than its factorization.

21920010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104398.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 21920010 is about 4681.8810322348. The cubic root of 21920010 is about 279.8639219730.

Adding to 21920010 its reverse (1002912), we get a palindrome (22922922).

The spelling of 21920010 in words is "twenty-one million, nine hundred twenty thousand, ten".