68401781 has 16 divisors (see below), whose sum is σ = 79685760. Its totient is φ = 57507840.

The previous prime is 68401757. The next prime is 68401787. The reversal of 68401781 is 18710486.

It is a cyclic number.

It is not a de Polignac number, because 68401781 - 2¹⁴ = 68385397 is a prime.

It is a super-2 number, since 2×68401781² = 9357607287943922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68401787) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 88565 + ... + 89333.

It is an arithmetic number, because the mean of its divisors is an integer number (4980360).

Almost surely, 2^68401781 is an apocalyptic number.

It is an amenable number.

68401781 is a deficient number, since it is larger than the sum of its proper divisors (11283979).

68401781 is a wasteful number, since it uses less digits than its factorization.

68401781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1004.

The product of its (nonzero) digits is 10752, while the sum is 35.

The square root of 68401781 is about 8270.5369233200. The cubic root of 68401781 is about 408.9678200740.

The spelling of 68401781 in words is "sixty-eight million, four hundred one thousand, seven hundred eighty-one".