1216001421 has 12 divisors (see below), whose sum is σ = 1832814048. Its totient is φ = 775421064.

The previous prime is 1216001401. The next prime is 1216001431. The reversal of 1216001421 is 1241006121.

1216001421 is a `hidden beast` number, since 1 + 21 + 600 + 1 + 42 + 1 = 666.

It is not a de Polignac number, because 1216001421 - 2¹⁴ = 1215985037 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1216001394 and 1216001403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216001401) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2936995 + ... + 2937408.

It is an arithmetic number, because the mean of its divisors is an integer number (152734504).

Almost surely, 2^1216001421 is an apocalyptic number.

It is an amenable number.

1216001421 is a deficient number, since it is larger than the sum of its proper divisors (616812627).

1216001421 is a wasteful number, since it uses less digits than its factorization.

1216001421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5874432 (or 5874429 counting only the distinct ones).

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

The square root of 1216001421 is about 34871.2119233043. The cubic root of 1216001421 is about 1067.3610752560.

Adding to 1216001421 its reverse (1241006121), we get a palindrome (2457007542).

The spelling of 1216001421 in words is "one billion, two hundred sixteen million, one thousand, four hundred twenty-one".