1216402421 has 8 divisors (see below), whose sum is σ = 1326554880. Its totient is φ = 1108618992.

The previous prime is 1216402393. The next prime is 1216402423. The reversal of 1216402421 is 1242046121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1216402421 - 2¹⁴ = 1216386037 is a prime.

It is a super-2 number, since 2×1216402421² = 2959269699629322482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216402423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 591185 + ... + 593238.

It is an arithmetic number, because the mean of its divisors is an integer number (165819360).

Almost surely, 2^1216402421 is an apocalyptic number.

It is an amenable number.

1216402421 is a deficient number, since it is larger than the sum of its proper divisors (110152459).

1216402421 is a wasteful number, since it uses less digits than its factorization.

1216402421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1184515.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 1216402421 is about 34876.9611778320. The cubic root of 1216402421 is about 1067.4783900179.

Adding to 1216402421 its reverse (1242046121), we get a palindrome (2458448542).

The spelling of 1216402421 in words is "one billion, two hundred sixteen million, four hundred two thousand, four hundred twenty-one".