20311434 has 72 divisors (see below), whose sum is σ = 52071552. Its totient is φ = 5672160.

The previous prime is 20311433. The next prime is 20311439. The reversal of 20311434 is 43411302.

It is a super-2 number, since 2×20311434² = 825108702272712, 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 (20311433) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 33159 + ... + 33765.

It is an arithmetic number, because the mean of its divisors is an integer number (723216).

Almost surely, 2^20311434 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20311434, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26035776).

20311434 is an abundant number, since it is smaller than the sum of its proper divisors (31760118).

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

20311434 is a wasteful number, since it uses less digits than its factorization.

20311434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 652 (or 636 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 20311434 is about 4506.8208306965. The cubic root of 20311434 is about 272.8434476569.

Adding to 20311434 its reverse (43411302), we get a palindrome (63722736).

The spelling of 20311434 in words is "twenty million, three hundred eleven thousand, four hundred thirty-four".