64136749 has 4 divisors (see below), whose sum is σ = 64290240. Its totient is φ = 63983260.

The previous prime is 64136747. The next prime is 64136753. The reversal of 64136749 is 94763146.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 64136749 - 2¹ = 64136747 is a prime.

It is a super-2 number, since 2×64136749² = 8227045144578002, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64136741) 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, 76117 + ... + 76954.

It is an arithmetic number, because the mean of its divisors is an integer number (16072560).

Almost surely, 2^64136749 is an apocalyptic number.

It is an amenable number.

64136749 is a deficient number, since it is larger than the sum of its proper divisors (153491).

64136749 is a wasteful number, since it uses less digits than its factorization.

64136749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153490.

The product of its digits is 108864, while the sum is 40.

The square root of 64136749 is about 8008.5422518708. The cubic root of 64136749 is about 400.2846910794.

The spelling of 64136749 in words is "sixty-four million, one hundred thirty-six thousand, seven hundred forty-nine".