78021761 has 8 divisors (see below), whose sum is σ = 81446400. Its totient is φ = 74653920.

The previous prime is 78021751. The next prime is 78021787. The reversal of 78021761 is 16712087.

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 78021761 - 2¹⁴ = 78005377 is a prime.

It is a super-2 number, since 2×78021761² = 12174790379082242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78021751) 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, 11381 + ... + 16898.

It is an arithmetic number, because the mean of its divisors is an integer number (10180800).

Almost surely, 2^78021761 is an apocalyptic number.

It is an amenable number.

78021761 is a deficient number, since it is larger than the sum of its proper divisors (3424639).

78021761 is a wasteful number, since it uses less digits than its factorization.

78021761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28399.

The product of its (nonzero) digits is 4704, while the sum is 32.

The square root of 78021761 is about 8832.9927544406. The cubic root of 78021761 is about 427.3055983751.

The spelling of 78021761 in words is "seventy-eight million, twenty-one thousand, seven hundred sixty-one".