1216690 has 24 divisors (see below), whose sum is σ = 2331972. Its totient is φ = 456960.

The previous prime is 1216681. The next prime is 1216693. The reversal of 1216690 is 966121.

It can be written as a sum of positive squares in 6 ways, for example, as 447561 + 769129 = 669^2 + 877^2 .

It is a super-2 number, since 2×1216690² = 2960669112200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1216693) 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, 2680 + ... + 3100.

2^1216690 is an apocalyptic number.

1216690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1216690 is a deficient number, since it is larger than the sum of its proper divisors (1115282).

1216690 is a wasteful number, since it uses less digits than its factorization.

1216690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462 (or 445 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 1216690 is about 1103.0367174306. The cubic root of 1216690 is about 106.7562506966.

The spelling of 1216690 in words is "one million, two hundred sixteen thousand, six hundred ninety".