1216715745 has 64 divisors (see below), whose sum is σ = 2350301184. Its totient is φ = 525692160.

The previous prime is 1216715719. The next prime is 1216715761. The reversal of 1216715745 is 5475176121.

It is not a de Polignac number, because 1216715745 - 2¹⁰ = 1216714721 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 135619 + ... + 144311.

It is an arithmetic number, because the mean of its divisors is an integer number (36723456).

Almost surely, 2^1216715745 is an apocalyptic number.

1216715745 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1216715745 is a deficient number, since it is larger than the sum of its proper divisors (1133585439).

1216715745 is a wasteful number, since it uses less digits than its factorization.

1216715745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8782.

The product of its digits is 58800, while the sum is 39.

The square root of 1216715745 is about 34881.4527363755. The cubic root of 1216715745 is about 1067.5700367405.

The spelling of 1216715745 in words is "one billion, two hundred sixteen million, seven hundred fifteen thousand, seven hundred forty-five".