30721044 has 12 divisors (see below), whose sum is σ = 71682464. Its totient is φ = 10240344.

The previous prime is 30721027. The next prime is 30721073. The reversal of 30721044 is 44012703.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 30721044.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1280032 + ... + 1280055.

Almost surely, 2^30721044 is an apocalyptic number.

It is an amenable number.

30721044 is an abundant number, since it is smaller than the sum of its proper divisors (40961420).

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

30721044 is a wasteful number, since it uses less digits than its factorization.

30721044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2560094 (or 2560092 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 30721044 is about 5542.6567636829. The cubic root of 30721044 is about 313.1929591021.

Adding to 30721044 its reverse (44012703), we get a palindrome (74733747).

The spelling of 30721044 in words is "thirty million, seven hundred twenty-one thousand, forty-four".