1211748981 has 8 divisors (see below), whose sum is σ = 1615836000. Its totient is φ = 807747312.

The previous prime is 1211748961. The next prime is 1211748983. The reversal of 1211748981 is 1898471121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1211748981 - 2¹⁵ = 1211716213 is a prime.

It is a super-2 number, since 2×1211748981² = 2936671185909076722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211748983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28270 + ... + 56768.

It is an arithmetic number, because the mean of its divisors is an integer number (201979500).

Almost surely, 2^1211748981 is an apocalyptic number.

It is an amenable number.

1211748981 is a deficient number, since it is larger than the sum of its proper divisors (404087019).

1211748981 is a wasteful number, since it uses less digits than its factorization.

1211748981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42675.

The product of its digits is 32256, while the sum is 42.

The square root of 1211748981 is about 34810.1850181811. The cubic root of 1211748981 is about 1066.1154105469.

The spelling of 1211748981 in words is "one billion, two hundred eleven million, seven hundred forty-eight thousand, nine hundred eighty-one".