1212531390 has 64 divisors (see below), whose sum is σ = 3695339520. Its totient is φ = 277149600.

The previous prime is 1212531377. The next prime is 1212531391. The reversal of 1212531390 is 931352121.

1212531390 is a `hidden beast` number, since 1 + 21 + 253 + 1 + 390 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212531391) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 318886 + ... + 322665.

It is an arithmetic number, because the mean of its divisors is an integer number (57739680).

Almost surely, 2^1212531390 is an apocalyptic number.

1212531390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1212531390 is an abundant number, since it is smaller than the sum of its proper divisors (2482808130).

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

1212531390 is a wasteful number, since it uses less digits than its factorization.

1212531390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641574 (or 641568 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 1212531390 is about 34821.4214241751. The cubic root of 1212531390 is about 1066.3448196735.

The spelling of 1212531390 in words is "one billion, two hundred twelve million, five hundred thirty-one thousand, three hundred ninety".