742780517 has 8 divisors (see below), whose sum is σ = 747855480. Its totient is φ = 737714880.

The previous prime is 742780499. The next prime is 742780573. The reversal of 742780517 is 715087247.

It is a Cunningham number, because it is equal to 27254²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 131652676 + 611127841 = 11474^2 + 24721^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 742780517 - 2⁶ = 742780453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (742710517) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 237359 + ... + 240467.

It is an arithmetic number, because the mean of its divisors is an integer number (93481935).

Almost surely, 2^742780517 is an apocalyptic number.

It is an amenable number.

742780517 is a deficient number, since it is larger than the sum of its proper divisors (5074963).

742780517 is a wasteful number, since it uses less digits than its factorization.

742780517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4663.

The product of its (nonzero) digits is 109760, while the sum is 41.

The square root of 742780517 is about 27254.0000183459. Note that the first 4 decimals coincide. The cubic root of 742780517 is about 905.6356317198.

The spelling of 742780517 in words is "seven hundred forty-two million, seven hundred eighty thousand, five hundred seventeen".