1231501020 has 24 divisors (see below), whose sum is σ = 3448203024. Its totient is φ = 328400256.

The previous prime is 1231500989. The next prime is 1231501027. The reversal of 1231501020 is 201051321.

It is a super-2 number, since 2×1231501020² = 3033189524522080800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231501027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10262449 + ... + 10262568.

It is an arithmetic number, because the mean of its divisors is an integer number (143675126).

Almost surely, 2^1231501020 is an apocalyptic number.

1231501020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231501020 is an abundant number, since it is smaller than the sum of its proper divisors (2216702004).

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

1231501020 is a wasteful number, since it uses less digits than its factorization.

1231501020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20525029 (or 20525027 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 1231501020 is about 35092.7488236530. The cubic root of 1231501020 is about 1071.8769339214.

Adding to 1231501020 its reverse (201051321), we get a palindrome (1432552341).

The spelling of 1231501020 in words is "one billion, two hundred thirty-one million, five hundred one thousand, twenty".