1406376781 has 2 divisors, whose sum is σ = 1406376782. Its totient is φ = 1406376780.

The previous prime is 1406376749. The next prime is 1406376787. The reversal of 1406376781 is 1876736041.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1191285225 + 215091556 = 34515^2 + 14666^2 .

It is a cyclic number.

It is not a de Polignac number, because 1406376781 - 2⁵ = 1406376749 is a prime.

It is a super-2 number, since 2×1406376781² = 3955791300271843922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1406376787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 703188390 + 703188391.

It is an arithmetic number, because the mean of its divisors is an integer number (703188391).

Almost surely, 2^1406376781 is an apocalyptic number.

It is an amenable number.

1406376781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1406376781 is an equidigital number, since it uses as much as digits as its factorization.

1406376781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 169344, while the sum is 43.

The square root of 1406376781 is about 37501.6903752351. The cubic root of 1406376781 is about 1120.3848541890.

The spelling of 1406376781 in words is "one billion, four hundred six million, three hundred seventy-six thousand, seven hundred eighty-one".