1231152021 has 16 divisors (see below), whose sum is σ = 1989741120. Its totient is φ = 746152560.

The previous prime is 1231151989. The next prime is 1231152047. The reversal of 1231152021 is 1202511321.

1231152021 is a `hidden beast` number, since 123 + 1 + 1 + 520 + 21 = 666.

It is not a de Polignac number, because 1231152021 - 2⁵ = 1231151989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1231151985 and 1231152003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231151021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2072350 + ... + 2072943.

It is an arithmetic number, because the mean of its divisors is an integer number (124358820).

Almost surely, 2^1231152021 is an apocalyptic number.

1231152021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1231152021 is a deficient number, since it is larger than the sum of its proper divisors (758589099).

1231152021 is a wasteful number, since it uses less digits than its factorization.

1231152021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4145313 (or 4145307 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 1231152021 is about 35087.7759483271. The cubic root of 1231152021 is about 1071.7756701479.

Adding to 1231152021 its reverse (1202511321), we get a palindrome (2433663342).

The spelling of 1231152021 in words is "one billion, two hundred thirty-one million, one hundred fifty-two thousand, twenty-one".