30721420 has 24 divisors (see below), whose sum is σ = 64620864. Its totient is φ = 12268416.

The previous prime is 30721417. The next prime is 30721429. The reversal of 30721420 is 2412703.

It is not an unprimeable number, because it can be changed into a prime (30721429) 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, 19917 + ... + 21403.

It is an arithmetic number, because the mean of its divisors is an integer number (2692536).

Almost surely, 2^30721420 is an apocalyptic number.

It is an amenable number.

30721420 is an abundant number, since it is smaller than the sum of its proper divisors (33899444).

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

30721420 is a wasteful number, since it uses less digits than its factorization.

30721420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2529 (or 2527 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 30721420 is about 5542.6906823311. The cubic root of 30721420 is about 313.1942368373.

The spelling of 30721420 in words is "thirty million, seven hundred twenty-one thousand, four hundred twenty".