20651040 has 72 divisors (see below), whose sum is σ = 70476588. Its totient is φ = 5506560.

The previous prime is 20651027. The next prime is 20651041. The reversal of 20651040 is 4015602.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17539344 + 3111696 = 4188^2 + 1764^2 .

It is a tau number, because it is divible by the number of its divisors (72).

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 (20651041) 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, 5731 + ... + 8610.

Almost surely, 2^20651040 is an apocalyptic number.

20651040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20651040 is an abundant number, since it is smaller than the sum of its proper divisors (49825548).

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

20651040 is a wasteful number, since it uses less digits than its factorization.

20651040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14362 (or 14351 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 20651040 is about 4544.3415364605. The cubic root of 20651040 is about 274.3556927104.

Adding to 20651040 its reverse (4015602), we get a palindrome (24666642).

The spelling of 20651040 in words is "twenty million, six hundred fifty-one thousand, forty".