30487721 has 4 divisors (see below), whose sum is σ = 33259344. Its totient is φ = 27716100.

The previous prime is 30487711. The next prime is 30487727. The reversal of 30487721 is 12778403.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30487721 is a prime.

It is a super-2 number, since 2×30487721² = 1859002263547682, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (30487727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1385795 + ... + 1385816.

It is an arithmetic number, because the mean of its divisors is an integer number (8314836).

Almost surely, 2^30487721 is an apocalyptic number.

It is an amenable number.

30487721 is a deficient number, since it is larger than the sum of its proper divisors (2771623).

30487721 is a wasteful number, since it uses less digits than its factorization.

30487721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2771622.

The product of its (nonzero) digits is 9408, while the sum is 32.

The square root of 30487721 is about 5521.5687082567. The cubic root of 30487721 is about 312.3980544263.

The spelling of 30487721 in words is "thirty million, four hundred eighty-seven thousand, seven hundred twenty-one".