30787220821 has 6 divisors (see below), whose sum is σ = 35813705910. Its totient is φ = 26389046376.

The previous prime is 30787220773. The next prime is 30787220833. The reversal of 30787220821 is 12802278703.

It can be written as a sum of positive squares in only one way, i.e., 21991407025 + 8795813796 = 148295^2 + 93786^2 .

It is not a de Polignac number, because 30787220821 - 2⁷ = 30787220693 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 (30787220861) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 314155266 + ... + 314155363.

It is an arithmetic number, because the mean of its divisors is an integer number (5968950985).

Almost surely, 2^30787220821 is an apocalyptic number.

It is an amenable number.

30787220821 is a deficient number, since it is larger than the sum of its proper divisors (5026485089).

30787220821 is an equidigital number, since it uses as much as digits as its factorization.

30787220821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 628310643 (or 628310636 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 40.

The spelling of 30787220821 in words is "thirty billion, seven hundred eighty-seven million, two hundred twenty thousand, eight hundred twenty-one".