1210821697 has 4 divisors (see below), whose sum is σ = 1212193840. Its totient is φ = 1209449556.

The previous prime is 1210821641. The next prime is 1210821713. The reversal of 1210821697 is 7961280121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1210821697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1210821197) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 684747 + ... + 686512.

It is an arithmetic number, because the mean of its divisors is an integer number (303048460).

Almost surely, 2^1210821697 is an apocalyptic number.

It is an amenable number.

1210821697 is a deficient number, since it is larger than the sum of its proper divisors (1372143).

1210821697 is an equidigital number, since it uses as much as digits as its factorization.

1210821697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1372142.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 1210821697 is about 34796.8633212823. The cubic root of 1210821697 is about 1065.8433949022.

The spelling of 1210821697 in words is "one billion, two hundred ten million, eight hundred twenty-one thousand, six hundred ninety-seven".