30721261 has 8 divisors (see below), whose sum is σ = 33943104. Its totient is φ = 27656640.

The previous prime is 30721253. The next prime is 30721277. The reversal of 30721261 is 16212703.

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 30721261 - 2³ = 30721253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30721231) 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, 38895 + ... + 39676.

It is an arithmetic number, because the mean of its divisors is an integer number (4242888).

Almost surely, 2^30721261 is an apocalyptic number.

It is an amenable number.

30721261 is a deficient number, since it is larger than the sum of its proper divisors (3221843).

30721261 is a wasteful number, since it uses less digits than its factorization.

30721261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78611.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 30721261 is about 5542.6763390983. The cubic root of 30721261 is about 313.1936965197.

Adding to 30721261 its reverse (16212703), we get a palindrome (46933964).

The spelling of 30721261 in words is "thirty million, seven hundred twenty-one thousand, two hundred sixty-one".