2406221721 has 48 divisors (see below), whose sum is σ = 3692270400. Its totient is φ = 1565448768.

The previous prime is 2406221681. The next prime is 2406221749. The reversal of 2406221721 is 1271226042.

2406221721 is a `hidden beast` number, since 2 + 4 + 0 + 622 + 17 + 21 = 666.

2406221721 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2406221721 - 2⁷ = 2406221593 is a prime.

It is a super-2 number, since 2×2406221721² = 11579805941224403682, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (2406221771) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2250375 + ... + 2251443.

It is an arithmetic number, because the mean of its divisors is an integer number (76922300).

Almost surely, 2^2406221721 is an apocalyptic number.

It is an amenable number.

2406221721 is a deficient number, since it is larger than the sum of its proper divisors (1286048679).

2406221721 is a wasteful number, since it uses less digits than its factorization.

2406221721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1300 (or 1288 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 2406221721 is about 49053.2539287660. The cubic root of 2406221721 is about 1340.0218532487.

Adding to 2406221721 its reverse (1271226042), we get a palindrome (3677447763).

The spelling of 2406221721 in words is "two billion, four hundred six million, two hundred twenty-one thousand, seven hundred twenty-one".