20120291820 has 36 divisors (see below), whose sum is σ = 61031552400. Its totient is φ = 5365411104.

The previous prime is 20120291819. The next prime is 20120291837. The reversal of 20120291820 is 2819202102.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×20120291820² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55889520 + ... + 55889879.

It is an arithmetic number, because the mean of its divisors is an integer number (1695320900).

Almost surely, 2^20120291820 is an apocalyptic number.

20120291820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20120291820 is an abundant number, since it is smaller than the sum of its proper divisors (40911260580).

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

20120291820 is a wasteful number, since it uses less digits than its factorization.

20120291820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111779414 (or 111779409 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

Adding to 20120291820 its reverse (2819202102), we get a palindrome (22939493922).

The spelling of 20120291820 in words is "twenty billion, one hundred twenty million, two hundred ninety-one thousand, eight hundred twenty".