240021421 has 8 divisors (see below), whose sum is σ = 246093624. Its totient is φ = 233959680.

The previous prime is 240021413. The next prime is 240021449. The reversal of 240021421 is 124120042.

It can be written as a sum of positive squares in 4 ways, for example, as 8555625 + 231465796 = 2925^2 + 15214^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 240021421 - 2³ = 240021413 is a prime.

It is a super-2 number, since 2×240021421² = 115220565077718482, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 240021395 and 240021404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (240021461) 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, 66171 + ... + 69703.

It is an arithmetic number, because the mean of its divisors is an integer number (30761703).

Almost surely, 2^240021421 is an apocalyptic number.

It is an amenable number.

240021421 is a deficient number, since it is larger than the sum of its proper divisors (6072203).

240021421 is a wasteful number, since it uses less digits than its factorization.

240021421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5231.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 240021421 is about 15492.6247292058. The cubic root of 240021421 is about 621.4649895373.

Adding to 240021421 its reverse (124120042), we get a palindrome (364141463).

The spelling of 240021421 in words is "two hundred forty million, twenty-one thousand, four hundred twenty-one".