140000021 has 4 divisors (see below), whose sum is σ = 160000032. Its totient is φ = 120000012.

The previous prime is 139999991. The next prime is 140000041. The reversal of 140000021 is 120000041.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 140000021 - 2⁶ = 139999957 is a prime.

It is a Duffinian number.

140000021 is a modest number, since divided by 21 gives 14 as remainder.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 139999963 and 140000008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (140000041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9999995 + ... + 10000008.

It is an arithmetic number, because the mean of its divisors is an integer number (40000008).

Almost surely, 2^140000021 is an apocalyptic number.

It is an amenable number.

140000021 is a deficient number, since it is larger than the sum of its proper divisors (20000011).

140000021 is an equidigital number, since it uses as much as digits as its factorization.

140000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20000010.

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 140000021 is about 11832.1604536112. The cubic root of 140000021 is about 519.2494361476.

Adding to 140000021 its reverse (120000041), we get a palindrome (260000062).

The spelling of 140000021 in words is "one hundred forty million, twenty-one", and thus it is an aban number.