21350140 has 24 divisors (see below), whose sum is σ = 51240672. Its totient is φ = 7320000.

The previous prime is 21350137. The next prime is 21350143. The reversal of 21350140 is 4105312.

It is an interprime number because it is at equal distance from previous prime (21350137) and next prime (21350143).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21350143) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76111 + ... + 76390.

It is an arithmetic number, because the mean of its divisors is an integer number (2135028).

Almost surely, 2^21350140 is an apocalyptic number.

21350140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21350140 is an abundant number, since it is smaller than the sum of its proper divisors (29890532).

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

21350140 is a wasteful number, since it uses less digits than its factorization.

21350140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152517 (or 152515 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21350140 is about 4620.6211703623. The cubic root of 21350140 is about 277.4173224465.

Adding to 21350140 its reverse (4105312), we get a palindrome (25455452).

The spelling of 21350140 in words is "twenty-one million, three hundred fifty thousand, one hundred forty".