1221142131 has 24 divisors (see below), whose sum is σ = 1925320176. Its totient is φ = 739664640.

The previous prime is 1221142129. The next prime is 1221142133. The reversal of 1221142131 is 1312411221.

1221142131 is a `hidden beast` number, since 1 + 2 + 211 + 421 + 31 = 666.

It is an interprime number because it is at equal distance from previous prime (1221142129) and next prime (1221142133).

It is not a de Polignac number, because 1221142131 - 2¹ = 1221142129 is a prime.

It is a super-2 number, since 2×1221142131² = 2982376208206442322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221142133) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 338071 + ... + 341663.

It is an arithmetic number, because the mean of its divisors is an integer number (80221674).

Almost surely, 2^1221142131 is an apocalyptic number.

1221142131 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221142131 is a deficient number, since it is larger than the sum of its proper divisors (704178045).

1221142131 is a wasteful number, since it uses less digits than its factorization.

1221142131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7043 (or 7040 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

The square root of 1221142131 is about 34944.8441261368. The cubic root of 1221142131 is about 1068.8630690264.

Adding to 1221142131 its reverse (1312411221), we get a palindrome (2533553352).

The spelling of 1221142131 in words is "one billion, two hundred twenty-one million, one hundred forty-two thousand, one hundred thirty-one".