1216913520 has 80 divisors (see below), whose sum is σ = 3970995840. Its totient is φ = 307429632.

The previous prime is 1216913507. The next prime is 1216913521. The reversal of 1216913520 is 253196121.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216913521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 128874 + ... + 137993.

It is an arithmetic number, because the mean of its divisors is an integer number (49637448).

Almost surely, 2^1216913520 is an apocalyptic number.

1216913520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1216913520 is an abundant number, since it is smaller than the sum of its proper divisors (2754082320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1216913520 is a wasteful number, since it uses less digits than its factorization.

1216913520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266902 (or 266896 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 1216913520 is about 34884.2875805140. The cubic root of 1216913520 is about 1067.6278774826.

The spelling of 1216913520 in words is "one billion, two hundred sixteen million, nine hundred thirteen thousand, five hundred twenty".