20211930 has 40 divisors (see below), whose sum is σ = 54349812. Its totient is φ = 5389632.

The previous prime is 20211899. The next prime is 20211931. The reversal of 20211930 is 3911202.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20169081 + 42849 = 4491^2 + 207^2 .

It is a super-2 number, since 2×20211930² = 817044228649800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (20211931) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 11667 + ... + 13286.

Almost surely, 2^20211930 is an apocalyptic number.

20211930 is an abundant number, since it is smaller than the sum of its proper divisors (34137882).

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

20211930 is a wasteful number, since it uses less digits than its factorization.

20211930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24972 (or 24963 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 20211930 is about 4495.7680100290. The cubic root of 20211930 is about 272.3971724366.

The spelling of 20211930 in words is "twenty million, two hundred eleven thousand, nine hundred thirty".