77149621 has 8 divisors (see below), whose sum is σ = 82142424. Its totient is φ = 72207360.

The previous prime is 77149603. The next prime is 77149649. The reversal of 77149621 is 12694177.

77149621 = T₂₃₈ + T₂₃₉ + ... + T₇₈₀.

It can be written as a sum of positive squares in 4 ways, for example, as 1703025 + 75446596 = 1305^2 + 8686^2 .

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 77149621 - 2⁷ = 77149493 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 (77149661) 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, 9460 + ... + 15613.

It is an arithmetic number, because the mean of its divisors is an integer number (10267803).

Almost surely, 2^77149621 is an apocalyptic number.

It is an amenable number.

77149621 is a deficient number, since it is larger than the sum of its proper divisors (4992803).

77149621 is a wasteful number, since it uses less digits than its factorization.

77149621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25271.

The product of its digits is 21168, while the sum is 37.

The square root of 77149621 is about 8783.4856976032. The cubic root of 77149621 is about 425.7074648215.

The spelling of 77149621 in words is "seventy-seven million, one hundred forty-nine thousand, six hundred twenty-one".