1210561640 has 32 divisors (see below), whose sum is σ = 2756587680. Its totient is φ = 478389312.

The previous prime is 1210561637. The next prime is 1210561669. The reversal of 1210561640 is 461650121.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 178994 + ... + 185633.

It is an arithmetic number, because the mean of its divisors is an integer number (86143365).

Almost surely, 2^1210561640 is an apocalyptic number.

1210561640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1210561640 is an abundant number, since it is smaller than the sum of its proper divisors (1546026040).

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

1210561640 is a wasteful number, since it uses less digits than its factorization.

1210561640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364721 (or 364717 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 1210561640 is about 34793.1263326537. The cubic root of 1210561640 is about 1065.7670831207.

The spelling of 1210561640 in words is "one billion, two hundred ten million, five hundred sixty-one thousand, six hundred forty".