61213691 has 18 divisors (see below), whose sum is σ = 77912388. Its totient is φ = 47557440.

The previous prime is 61213681. The next prime is 61213699. The reversal of 61213691 is 19631216.

It is not a de Polignac number, because 61213691 - 2⁶ = 61213627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61213699) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 181475 + ... + 181811.

It is an arithmetic number, because the mean of its divisors is an integer number (4328466).

Almost surely, 2^61213691 is an apocalyptic number.

61213691 is a deficient number, since it is larger than the sum of its proper divisors (16698697).

61213691 is an equidigital number, since it uses as much as digits as its factorization.

61213691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 699 (or 355 counting only the distinct ones).

The product of its digits is 1944, while the sum is 29.

The square root of 61213691 is about 7823.9178804484. The cubic root of 61213691 is about 394.1088514555.

The spelling of 61213691 in words is "sixty-one million, two hundred thirteen thousand, six hundred ninety-one".