781387051 has 2 divisors, whose sum is σ = 781387052. Its totient is φ = 781387050.

The previous prime is 781387007. The next prime is 781387069. The reversal of 781387051 is 150783187.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (150783187) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-781387051 is a prime.

It is a super-2 number, since 2×781387051² = 1221131446940953202, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 781386995 and 781387013.

It is not a weakly prime, because it can be changed into another prime (781387001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390693525 + 390693526.

It is an arithmetic number, because the mean of its divisors is an integer number (390693526).

Almost surely, 2^781387051 is an apocalyptic number.

781387051 is a deficient number, since it is larger than the sum of its proper divisors (1).

781387051 is an equidigital number, since it uses as much as digits as its factorization.

781387051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 47040, while the sum is 40.

The square root of 781387051 is about 27953.3012540558. The cubic root of 781387051 is about 921.0617275326.

It can be divided in two parts, 7813 and 87051, that added together give a square (94864 = 308²).

The spelling of 781387051 in words is "seven hundred eighty-one million, three hundred eighty-seven thousand, fifty-one".