1216534431 has 8 divisors (see below), whose sum is σ = 1853766784. Its totient is φ = 695162520.

The previous prime is 1216534373. The next prime is 1216534463. The reversal of 1216534431 is 1344356121.

1216534431 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

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

It is a de Polignac number, because none of the positive numbers 2^k-1216534431 is a prime.

It is a super-2 number, since 2×1216534431² = 2959912043616987522, 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 (1216534931) 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, 28965085 + ... + 28965126.

It is an arithmetic number, because the mean of its divisors is an integer number (231720848).

Almost surely, 2^1216534431 is an apocalyptic number.

1216534431 is a deficient number, since it is larger than the sum of its proper divisors (637232353).

1216534431 is an equidigital number, since it uses as much as digits as its factorization.

1216534431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57930221.

The product of its digits is 8640, while the sum is 30.

The square root of 1216534431 is about 34878.8536365518. The cubic root of 1216534431 is about 1067.5170046305.

The spelling of 1216534431 in words is "one billion, two hundred sixteen million, five hundred thirty-four thousand, four hundred thirty-one".