1967720881 has 9 divisors (see below), whose sum is σ = 2289342699. Its totient is φ = 1686351744.

The previous prime is 1967720837. The next prime is 1967720899. The reversal of 1967720881 is 1880277691.

The square root of 1967720881 is 44359.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 687226225 + 1280494656 = 26215^2 + 35784^2 .

It is not a de Polignac number, because 1967720881 - 2¹⁹ = 1967196593 is a prime.

It is a super-2 number, since 2×1967720881² = 7743850931046832322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (1967720281) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 307345 + ... + 313681.

It is an arithmetic number, because the mean of its divisors is an integer number (254371411).

Almost surely, 2^1967720881 is an apocalyptic number.

1967720881 is the 44359-th square number.

1967720881 is the 22180-th centered octagonal number.

It is an amenable number.

1967720881 is a deficient number, since it is larger than the sum of its proper divisors (321621818).

1967720881 is an frugal number, since it uses more digits than its factorization.

1967720881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12688 (or 6344 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 49.

The cubic root of 1967720881 is about 1253.1060634498.

Multiplying 1967720881 by its sum of digits (49), we get a square (96418323169 = 310513²).

1967720881 divided by its sum of digits (49) gives a square (40157569 = 6337²).

The spelling of 1967720881 in words is "one billion, nine hundred sixty-seven million, seven hundred twenty thousand, eight hundred eighty-one".