1211605420 has 24 divisors (see below), whose sum is σ = 2561454000. Its totient is φ = 481388352.

The previous prime is 1211605399. The next prime is 1211605459. The reversal of 1211605420 is 245061121.

It is a junction number, because it is equal to n+sod(n) for n = 1211605391 and 1211605400.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 200310 + ... + 206269.

It is an arithmetic number, because the mean of its divisors is an integer number (106727250).

Almost surely, 2^1211605420 is an apocalyptic number.

1211605420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211605420 is an abundant number, since it is smaller than the sum of its proper divisors (1349848580).

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

1211605420 is a wasteful number, since it uses less digits than its factorization.

1211605420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406737 (or 406735 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 1211605420 is about 34808.1229025640. The cubic root of 1211605420 is about 1066.0733064914.

Adding to 1211605420 its reverse (245061121), we get a palindrome (1456666541).

The spelling of 1211605420 in words is "one billion, two hundred eleven million, six hundred five thousand, four hundred twenty".