1377944951881 has 9 divisors (see below), whose sum is σ = 1380601809223. Its totient is φ = 1375293204400.

The previous prime is 1377944951857. The next prime is 1377944951897. The reversal of 1377944951881 is 1881594497731.

The square root of 1377944951881 is 1173859.

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., 1212881513481 + 165063438400 = 1101309^2 + 406280^2 .

It is not a de Polignac number, because 1377944951881 - 2¹¹ = 1377944949833 is a prime.

It is a super-2 number, since 2×1377944951881² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1377944951281) 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, 949651206 + ... + 949652656.

Almost surely, 2^{1377944951881} is an apocalyptic number.

1377944951881 is the 1173859-th square number.

1377944951881 is the 586930-th centered octagonal number.

It is an amenable number.

1377944951881 is a deficient number, since it is larger than the sum of its proper divisors (2656857342).

1377944951881 is an frugal number, since it uses more digits than its factorization.

1377944951881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4520 (or 2260 counting only the distinct ones).

The product of its digits is 60963840, while the sum is 67.

The spelling of 1377944951881 in words is "one trillion, three hundred seventy-seven billion, nine hundred forty-four million, nine hundred fifty-one thousand, eight hundred eighty-one".