30121987 has 16 divisors (see below), whose sum is σ = 35848192. Its totient is φ = 24766560.

The previous prime is 30121979. The next prime is 30121991. The reversal of 30121987 is 78912103.

It is not a de Polignac number, because 30121987 - 2³ = 30121979 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30121907) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27013 + ... + 28105.

It is an arithmetic number, because the mean of its divisors is an integer number (2240512).

Almost surely, 2^30121987 is an apocalyptic number.

30121987 is a deficient number, since it is larger than the sum of its proper divisors (5726205).

30121987 is a wasteful number, since it uses less digits than its factorization.

30121987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1258.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 30121987 is about 5488.3501163829. The cubic root of 30121987 is about 311.1438387859.

The spelling of 30121987 in words is "thirty million, one hundred twenty-one thousand, nine hundred eighty-seven".