61207921 has 2 divisors, whose sum is σ = 61207922. Its totient is φ = 61207920.

The previous prime is 61207907. The next prime is 61207933. The reversal of 61207921 is 12970216.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41280625 + 19927296 = 6425^2 + 4464^2 .

It is a cyclic number.

It is not a de Polignac number, because 61207921 - 2⁵ = 61207889 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61207921.

It is not a weakly prime, because it can be changed into another prime (61207961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30603960 + 30603961.

It is an arithmetic number, because the mean of its divisors is an integer number (30603961).

Almost surely, 2^61207921 is an apocalyptic number.

It is an amenable number.

61207921 is a deficient number, since it is larger than the sum of its proper divisors (1).

61207921 is an equidigital number, since it uses as much as digits as its factorization.

61207921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 61207921 is about 7823.5491306695. The cubic root of 61207921 is about 394.0964681716.

It can be divided in two parts, 61207 and 921, that added together give a triangular number (62128 = T₃₅₂).

The spelling of 61207921 in words is "sixty-one million, two hundred seven thousand, nine hundred twenty-one".