1221270785 has 16 divisors (see below), whose sum is σ = 1706489856. Its totient is φ = 821640768.

The previous prime is 1221270773. The next prime is 1221270793. The reversal of 1221270785 is 5870721221.

It is not a de Polignac number, because 1221270785 - 2⁸ = 1221270529 is a prime.

It is a super-3 number, since 3×1221270785³ (a number of 28 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 327329 + ... + 331038.

It is an arithmetic number, because the mean of its divisors is an integer number (106655616).

Almost surely, 2^1221270785 is an apocalyptic number.

It is an amenable number.

1221270785 is a deficient number, since it is larger than the sum of its proper divisors (485219071).

1221270785 is an equidigital number, since it uses as much as digits as its factorization.

1221270785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658432.

The product of its (nonzero) digits is 15680, while the sum is 35.

The square root of 1221270785 is about 34946.6848928478. The cubic root of 1221270785 is about 1068.9006045643.

The spelling of 1221270785 in words is "one billion, two hundred twenty-one million, two hundred seventy thousand, seven hundred eighty-five".