1210661550 has 216 divisors, whose sum is σ = 3858334896. Its totient is φ = 266595840.

The previous prime is 1210661539. The next prime is 1210661591. The reversal of 1210661550 is 551660121.

It is a happy number.

1210661550 is a `hidden beast` number, since 1 + 2 + 106 + 6 + 1 + 550 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 2648922 + ... + 2649378.

Almost surely, 2^1210661550 is an apocalyptic number.

1210661550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1210661550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1929167448).

1210661550 is an abundant number, since it is smaller than the sum of its proper divisors (2647673346).

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

1210661550 is a wasteful number, since it uses less digits than its factorization.

1210661550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540 (or 503 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 1210661550 is about 34794.5620751289. The cubic root of 1210661550 is about 1065.7964022556.

The spelling of 1210661550 in words is "one billion, two hundred ten million, six hundred sixty-one thousand, five hundred fifty".