78172653 has 16 divisors (see below), whose sum is σ = 117129600. Its totient is φ = 46014144.

The previous prime is 78172651. The next prime is 78172663. The reversal of 78172653 is 35627187.

It is not a de Polignac number, because 78172653 - 2¹ = 78172651 is a prime.

It is a super-2 number, since 2×78172653² = 12221927354116818, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78172651) 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, 42678 + ... + 44471.

It is an arithmetic number, because the mean of its divisors is an integer number (7320600).

Almost surely, 2^78172653 is an apocalyptic number.

It is an amenable number.

78172653 is a deficient number, since it is larger than the sum of its proper divisors (38956947).

78172653 is a wasteful number, since it uses less digits than its factorization.

78172653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87188.

The product of its digits is 70560, while the sum is 39.

The square root of 78172653 is about 8841.5300146524. The cubic root of 78172653 is about 427.5808868524.

The spelling of 78172653 in words is "seventy-eight million, one hundred seventy-two thousand, six hundred fifty-three".