787867681 has 4 divisors (see below), whose sum is σ = 790933572. Its totient is φ = 784801792.

The previous prime is 787867589. The next prime is 787867687. The reversal of 787867681 is 186768787.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186768787 = 29 ⋅6440303.

It can be written as a sum of positive squares in 2 ways, for example, as 730350625 + 57517056 = 27025^2 + 7584^2 .

It is a cyclic number.

It is not a de Polignac number, because 787867681 - 2¹⁵ = 787834913 is a prime.

It is a super-2 number, since 2×787867681² = 1241470965528635522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (787867687) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1532560 + ... + 1533073.

It is an arithmetic number, because the mean of its divisors is an integer number (197733393).

Almost surely, 2^787867681 is an apocalyptic number.

It is an amenable number.

787867681 is a deficient number, since it is larger than the sum of its proper divisors (3065891).

787867681 is a wasteful number, since it uses less digits than its factorization.

787867681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3065890.

The product of its digits is 6322176, while the sum is 58.

The square root of 787867681 is about 28068.9807616878. The cubic root of 787867681 is about 923.6010725369.

The spelling of 787867681 in words is "seven hundred eighty-seven million, eight hundred sixty-seven thousand, six hundred eighty-one".